js-apis-medialibrary.md 80.0 KB
Newer Older
W
wusongqing 已提交
1 2 3 4 5 6 7 8 9 10
# Media Library Management

> ![icon-note.gif](public_sys-resources/icon-note.gif) **NOTE**
> This component is supported since API version 6. Updates will be marked with a superscript to indicate their earliest API version.

## Modules to Import
```
import mediaLibrary from '@ohos.multimedia.medialibrary';
```

W
wusongqing 已提交
11
## mediaLibrary.getMediaLibrary<sup>8+</sup>
W
wusongqing 已提交
12 13 14

getMediaLibrary(context: Context): MediaLibrary

W
wusongqing 已提交
15
Obtains a **MediaLibrary** instance, which is used to access and modify personal media data such as audios, videos, images, and documents.
W
wusongqing 已提交
16 17 18 19 20

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
21 22 23
| Name | Type   | Mandatory| Description                      |
| ------- | ------- | ---- | -------------------------- |
| context | Context | Yes  | Context of the ability.|
W
wusongqing 已提交
24 25 26

**Return value**

W
wusongqing 已提交
27 28
| Type                           | Description   |
| ----------------------------- | :---- |
W
wusongqing 已提交
29 30 31 32 33 34 35 36 37 38
| [MediaLibrary](#medialibrary) | **MediaLibrary** instance.|

**Example**

```
import featureAbility from '@ohos.ability.featureAbility';

var context = featureAbility.getContext()
var media = mediaLibrary.getMediaLibrary(context);
```
W
wusongqing 已提交
39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
## mediaLibrary.getMediaLibrary

getMediaLibrary(): MediaLibrary

Obtains a **MediaLibrary** instance, which is used to access and modify personal media data such as audios, videos, images, and documents.

> **Note**: This API is no longer maintained since API version 8. You are advised to use [mediaLibrary.getMediaLibrary<sup>8+</sup>](#medialibrarygetmedialibrary8) instead.

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Return value**

| Type                         | Description      |
| ----------------------------- | :--------- |
| [MediaLibrary](#medialibrary) | **MediaLibrary** instance.|

**Example**

```js
var media = mediaLibrary.getMediaLibrary();
```

W
wusongqing 已提交
61 62
## MediaLibrary

W
wusongqing 已提交
63
### getFileAssets<sup>7+</sup>
W
wusongqing 已提交
64 65 66 67 68 69 70 71 72 73 74 75


getFileAssets(options: MediaFetchOptions, callback: AsyncCallback&lt;FetchFileResult&gt;): void 

Obtains file assets (also called files). This API uses an asynchronous callback to return the result.

**Required permissions**: ohos.permission.READ_MEDIA

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
76 77 78 79
| Name  | Type                                               | Mandatory| Description                             |
| -------- | --------------------------------------------------- | ---- | --------------------------------- |
| options  | [MediaFetchOptions](#mediafetchoptions7)            | Yes  | Options for fetching the files.                     |
| callback | AsyncCallback<[FetchFileResult](#fetchfileresult7)> | Yes  | Asynchronous callback of **FetchFileResult**.|
W
wusongqing 已提交
80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100

**Example**

```
let fileKeyObj = mediaLibrary.FileKey
let imageType = mediaLibrary.MediaType.IMAGE
let imagesfetchOp = {
    selections: fileKeyObj.MEDIA_TYPE + '= ?',
    selectionArgs: [imageType.toString()],
};
mediaLibrary.getFileAssets(imagesfetchOp, (error, fetchFileResult) => {
    if (fetchFileResult != undefined) {
        console.info('mediaLibraryTest : ASSET_CALLBACK fetchFileResult success');
        fetchFileResult.getAllObject((err, fileAssetList) => {
            if (fileAssetList != undefined) {
                fileAssetList.forEach(getAllObjectInfo);
            }
    	});
    }
});
```
W
wusongqing 已提交
101
### getFileAssets<sup>7+</sup>
W
wusongqing 已提交
102 103 104 105 106 107 108 109 110 111 112

getFileAssets(options: MediaFetchOptions): Promise&lt;FetchFileResult&gt;

Obtains file assets. This API uses a promise to return the result.

**Required permissions**: ohos.permission.READ_MEDIA

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
113 114 115
| Name | Type                                    | Mandatory| Description        |
| ------- | ---------------------------------------- | ---- | ------------ |
| options | [MediaFetchOptions](#mediafetchoptions7) | Yes  | Options for fetching the files.|
W
wusongqing 已提交
116 117 118

**Return value**

W
wusongqing 已提交
119 120 121
| Type                                | Description          |
| ------------------------------------ | -------------- |
| [FetchFileResult](#fetchfileresult7) | Result set of the file retrieval operation.|
W
wusongqing 已提交
122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148

**Example**

```
let fileKeyObj = mediaLibrary.FileKey
let imageType = mediaLibrary.MediaType.IMAGE
let imagesfetchOp = {
    selections: fileKeyObj.MEDIA_TYPE + '= ?',
    selectionArgs: [imageType.toString()],
};
mediaLibrary.getFileAssets(imagesfetchOp).then(function(fetchFileResult){
    console.info("getFileAssets successfully:"+ JSON.stringify(dir));
}).catch(function(err){
    console.info("getFileAssets failed with error:"+ err);
});
```

### on<sup>8+</sup>

on(type: 'deviceChange'|'albumChange'|'imageChange'|'audioChange'|'videoChange'|'fileChange'|'remoteFileChange', callback: Callback&lt;void&gt;): void

Subscribes to the media library changes. This API uses an asynchronous callback to return the result.

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
149 150 151 152
| Name     | Type                  | Mandatory  | Description                                      |
| -------- | -------------------- | ---- | ---------------------------------------- |
| type     | string               | Yes   | Media type.<br>'deviceChange': registered device change<br>'albumChange': album change<br>'imageChange': image file change<br>'audioChange': audio file change<br>'videoChange': video file change<br>'fileChange': file change<br>'remoteFileChange': file change on the registered device|
| callback | callback&lt;void&gt; | Yes   | Void callback.                                   |
W
wusongqing 已提交
153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170

**Example**

```
mediaLibrary.on('imageChange', () => {
    // image file had changed, do something
})
```
### off<sup>8+</sup>

off(type: 'deviceChange'|'albumChange'|'imageChange'|'audioChange'|'videoChange'|'fileChange'|'remoteFileChange', callback?: Callback&lt;void&gt;): void

Unsubscribes from the media library changes. This API uses an asynchronous callback to return the result.

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
171 172 173 174
| Name     | Type                  | Mandatory  | Description                                      |
| -------- | -------------------- | ---- | ---------------------------------------- |
| type     | string               | Yes   | Media type.<br>'deviceChange': registered device change<br>'albumChange': album change<br>'imageChange': image file change<br>'audioChange': audio file change<br>'videoChange': video file change<br>'fileChange': file change<br>'remoteFileChange': file change on the registered device|
| callback | callback&lt;void&gt; | No   | Void callback.                                   |
W
wusongqing 已提交
175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195

**Example**

```
mediaLibrary.off('imageChange', () => {
    // stop listening success
})
```

### createAsset <sup>8+</sup>

createAsset(mediaType: MediaType, displayName: string, relativePath: string, callback: AsyncCallback&lt;FileAsset&gt;): void

Creates a media asset. This API uses an asynchronous callback to return the result.

**Required permissions**: ohos.permission.READ_MEDIA and ohos.permission.WRITE_MEDIA

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
196 197 198 199 200 201
| Name      | Type                                   | Mandatory| Description                                                        |
| ------------ | --------------------------------------- | ---- | ------------------------------------------------------------ |
| mediaType    | [MediaType](#mediatype8)                | Yes  | Media type.                                                    |
| displayName  | string                                  | Yes  | Display file name.                                                  |
| relativePath | string                                  | Yes  | Path for storing the file. You can use [getPublicDirectory](#getpublicdirectory8) to obtain the paths for storing different types of files.|
| callback     | AsyncCallback<[FileAsset](#fileasset7)> | Yes  | Asynchronous callback for **FileAsset**.                         |
W
wusongqing 已提交
202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232

**Example**

```
async function example() {
    // Create an image file in callback mode.
    let mediaType = mediaLibrary.MediaType.IMAGE;
    let DIR_IMAGE = mediaLibrary.DirectoryType.DIR_IMAGE;
    const path = await media.getPublicDirectory(DIR_IMAGE);
    mediaLibrary.createAsset(mediaType, 'imageCallBack.jpg', path + 'myPicture/', (err, fileAsset) => {
        if (fileAsset != undefined) {
            console.info('createAsset successfully, message = ' + err);
        } else {
            console.info('createAsset failed, message = ' + err);
        }
    });
}
```

### createAsset<sup>8+</sup>

createAsset(mediaType: MediaType, displayName: string, relativePath: string): Promise&lt;FileAsset&gt;

Creates a media asset. This API uses a promise to return the result.

**Required permissions**: ohos.permission.READ_MEDIA and ohos.permission.WRITE_MEDIA

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
233 234 235 236 237
| Name      | Type                    | Mandatory| Description                                                        |
| ------------ | ------------------------ | ---- | ------------------------------------------------------------ |
| mediaType    | [MediaType](#mediatype8) | Yes  | Media type.                                                    |
| displayName  | string                   | Yes  | Display file name.                                                  |
| relativePath | string                   | Yes  | Relative path. You can use [getPublicDirectory](#getpublicdirectory8) to obtain the relative path of the level-1 directory of different types of media files.|
W
wusongqing 已提交
238 239 240

**Return value**

W
wusongqing 已提交
241 242 243
| Type                    | Description             |
| ------------------------ | ----------------- |
| [FileAsset](#fileasset7) | Media data (FileAsset).|
W
wusongqing 已提交
244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270

**Example**

```
async function example() {
    // Create an image file in promise mode
    let mediaType = mediaLibrary.MediaType.IMAGE;
    let DIR_IMAGE = mediaLibrary.DirectoryType.DIR_IMAGE;
    const path = await media.getPublicDirectory(DIR_IMAGE);
    mediaLibrary.createAsset(mediaType, "image01.jpg", path + 'myPicture/').then (function (asset) {
        console.info("createAsset successfully:"+ JSON.stringify(asset));
    }).catch(function(err){
        console.info("createAsset failed with error:"+ err);
    });
}
```

### getPublicDirectory<sup>8+</sup>

getPublicDirectory(type: DirectoryType, callback: AsyncCallback&lt;string&gt;): void

Obtains a public directory. This API uses an asynchronous callback to return the result.

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
271 272 273 274
| Name  | Type                            | Mandatory| Description                     |
| -------- | -------------------------------- | ---- | ------------------------- |
| type     | [DirectoryType](#directorytype8) | Yes  | Type of the public directory.             |
| callback | AsyncCallback&lt;string&gt;      | Yes  | Callback used to return the public directory.|
W
wusongqing 已提交
275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298

**Example**

```
let DIR_CAMERA = mediaLibrary.DirectoryType.DIR_CAMERA;
media.getPublicDirectory(DIR_CAMERA, (err, dicResult) => {
    if (dicResult == 'Camera/') {
        console.info('mediaLibraryTest : getPublicDirectory passed');
    } else {
        console.info('mediaLibraryTest : getPublicDirectory failed');
    }
});
```

### getPublicDirectory<sup>8+</sup>

getPublicDirectory(type: DirectoryType): Promise&lt;string&gt;

Obtains a public directory. This API uses a promise to return the result.

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
299 300 301
| Name| Type                            | Mandatory| Description        |
| ------ | -------------------------------- | ---- | ------------ |
| type   | [DirectoryType](#directorytype8) | Yes  | Type of the public directory.|
W
wusongqing 已提交
302 303 304

**Return value**

W
wusongqing 已提交
305 306 307
| Type            | Description            |
| ---------------- | ---------------- |
| Promise\<string> | Promise used to return the public directory.|
W
wusongqing 已提交
308 309 310 311 312 313 314 315 316 317 318 319 320 321 322

**Example**

```
async function example() {
    let DIR_CAMERA = mediaLibrary.DirectoryType.DIR_CAMERA;
    const dicResult = await media.getPublicDirectory(DIR_CAMERA);
    if (dicResult == 'Camera/') {
        console.info('MediaLibraryTest : getPublicDirectory');
    } else {
        console.info('MediaLibraryTest : getPublicDirectory failed');
    }
}
```

W
wusongqing 已提交
323
### getAlbums<sup>7+</sup>
W
wusongqing 已提交
324 325 326 327 328 329 330 331 332 333 334

getAlbums(options: MediaFetchOptions, callback: AsyncCallback<Array&lt;Album&gt;>): void

Obtains the albums. This API uses an asynchronous callback to return the result.

**Required permissions**: ohos.permission.READ_MEDIA

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
335 336 337 338
| Name  | Type                                        | Mandatory| Description                       |
| -------- | -------------------------------------------- | ---- | --------------------------- |
| options  | [MediaFetchOptions](#mediafetchoptions7)     | Yes  | Options for fetching the albums.               |
| callback | AsyncCallback&lt;Array<[Album](#album7)>&gt; | Yes  | Callback used to return the albums.|
W
wusongqing 已提交
339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357

**Example**

```
let AlbumNoArgsfetchOp = {
    selections: '',
    selectionArgs: [],
};
mediaLibrary.getAlbums(AlbumNoArgsfetchOp, (err, albumList) => {
    if (albumList != undefined) {
        const album = albumList[0];
        console.info('album.albumName = ' + album.albumName);
        console.info('album.count = ' + album.count);
     } else {
        console.info('getAlbum fail, message = ' + err);
     }
})
```

W
wusongqing 已提交
358
### getAlbums<sup>7+</sup>
W
wusongqing 已提交
359 360 361 362 363 364 365 366 367 368 369

getAlbums(options: MediaFetchOptions): Promise<Array&lt;Album&gt;>

Obtains the albums. This API uses a promise to return the result.

**Required permissions**: ohos.permission.READ_MEDIA

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
370 371 372
| Name | Type                                    | Mandatory| Description        |
| ------- | ---------------------------------------- | ---- | ------------ |
| options | [MediaFetchOptions](#mediafetchoptions7) | Yes  | Options for fetching the albums.|
W
wusongqing 已提交
373 374 375

**Return value**

W
wusongqing 已提交
376 377 378
| Type                            | Description         |
| -------------------------------- | ------------- |
| Promise<Array<[Album](#album7)>> | Promise used to return the albums.|
W
wusongqing 已提交
379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404

**Example**

```
let AlbumNoArgsfetchOp = {
    selections: '',
    selectionArgs: [],
};
mediaLibrary.getAlbums(AlbumNoArgsfetchOp).then(function(albumList){
    console.info("getAlbums successfully:"+ JSON.stringify(albumList));
}).catch(function(err){
    console.info("getAlbums failed with error:"+ err);
});
```

### release<sup>8+</sup>

release(callback: AsyncCallback&lt;void&gt;): void

Releases this **MediaLibrary** instance.
Call this API when you no longer need to use the APIs in the **MediaLibrary** instance.

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
405 406 407
| Name     | Type                       | Mandatory  | Description        |
| -------- | ------------------------- | ---- | ---------- |
| callback | AsyncCallback&lt;void&gt; | Yes   | Callback used to return the execution result.|
W
wusongqing 已提交
408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428

**Example**

```
var media = mediaLibrary.getMediaLibrary(context);
media.release((err) => {
    // do something
});
```

### release<sup>8+</sup>

release(): Promise&lt;void&gt;

Releases this **MediaLibrary** instance.
Call this API when you no longer need to use the APIs in the **MediaLibrary** instance.

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Return value**

W
wusongqing 已提交
429 430
| Type                 | Description                  |
| ------------------- | -------------------- |
W
wusongqing 已提交
431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451
| Promise&lt;void&gt; | Promise used to return the execution result.|

**Example**

```
var media = mediaLibrary.getMediaLibrary(context);
media.release()
```

### storeMediaAsset

storeMediaAsset(option: MediaAssetOption, callback: AsyncCallback&lt;string&gt;): void

Stores a media asset. This API uses an asynchronous callback to return the URI that stores the media asset.

This API is defined but not implemented in OpenHarmony 3.1 Release. It will be available for use in OpenHarmony 3.1 MR.

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
452 453 454 455
| Name     | Type                                   | Mandatory  | Description                     |
| -------- | ------------------------------------- | ---- | ----------------------- |
| option   | [MediaAssetOption](#mediaassetoption) | Yes   | Media asset option.                |
| callback | AsyncCallback&lt;string&gt;           | Yes   | Callback used to return the URI that stores the media asset.|
W
wusongqing 已提交
456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487

**Example**

  ```
let option = {
    src : "file:///data/data/ohos.xxx.yyy/files/image.png",
    mimeType : "image/jpeg",
    relativePath : "imageDir/image2/"
};
mediaLibrary.getMediaLibrary().storeMediaAsset(option, (err, value) => {
    if (err) {
        console.log("An error occurred when storing the media asset.");
        return;
    }
    console.log("Media asset stored. ");
    // Obtain the URI that stores the media asset.
});
  ```


### storeMediaAsset

storeMediaAsset(option: MediaAssetOption): Promise&lt;string&gt;

Stores a media asset. This API uses a promise to return the URI that stores the media asset.

This API is defined but not implemented in OpenHarmony 3.1 Release. It will be available for use in OpenHarmony 3.1 MR.

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
488 489 490
| Name   | Type                                   | Mandatory  | Description     |
| ------ | ------------------------------------- | ---- | ------- |
| option | [MediaAssetOption](#mediaassetoption) | Yes   | Media asset option.|
W
wusongqing 已提交
491 492 493

**Return value**

W
wusongqing 已提交
494 495
| Type                   | Description                          |
| --------------------- | ---------------------------- |
W
wusongqing 已提交
496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526
| Promise&lt;string&gt; | Promise used to return the URI that stores the media asset.|

**Example**

  ```
let option = {
    src : "file:///data/data/ohos.xxx.yyy/files/image.jpg",
    mimeType : "image/jpeg",
    relativePath : "imageDir/image2/"
};
mediaLibrary.getMediaLibrary().storeMediaAsset(option).then((value) => {
    console.log("Media asset stored.");
    // Obtain the URI that stores the media asset.
}).catch((err) => {
    console.log("An error occurred when storing the media assets.");
});
  ```


### startImagePreview

startImagePreview(images: Array&lt;string&gt;, index: number, callback: AsyncCallback&lt;void&gt;): void

Starts image preview, with the first image to preview specified. This API can be used to preview local images whose URIs start with **dataability://** or online images whose URIs start with **https://**. It uses an asynchronous callback to return the execution result.

This API is defined but not implemented in OpenHarmony 3.1 Release. It will be available for use in OpenHarmony 3.1 MR.

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
527 528 529 530 531
| Name     | Type                       | Mandatory  | Description                                      |
| -------- | ------------------------- | ---- | ---------------------------------------- |
| images   | Array&lt;string&gt;       | Yes   | URIs of the images to preview. The value can start with either **https://** or **dataability://**.|
| index    | number                    | Yes   | Index of the first image to preview.                              |
| callback | AsyncCallback&lt;void&gt; | Yes   | Callback used to return the image preview result. If the preview fails, an error message is returned.                       |
W
wusongqing 已提交
532 533 534 535 536 537 538 539

**Example**

  ```
let images = [
    "dataability:///media/external/images/media/50",
    "dataability:///media/external/images/media/55"
];
W
wusongqing 已提交
540
/* Online image usage mode
W
wusongqing 已提交
541 542 543 544
let images = [
    "https://media.xxxx.com/image1.jpg",
    "https://media.xxxx.com/image2.jpg"
];
W
wusongqing 已提交
545
*/
W
wusongqing 已提交
546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568
let index = 1;
mediaLibrary.getMediaLibrary().startImagePreview(images, index, (err) => {
    if (err) {
        console.log("An error occurred when previewing the images.");
        return;
    }
    console.log("Succeeded in previewing the images.");
});
  ```


### startImagePreview

startImagePreview(images: Array&lt;string&gt;, callback: AsyncCallback&lt;void&gt;): void

Starts image preview. This API can be used to preview local images whose URIs start with **dataability://** or online images whose URIs start with **https://**. It uses an asynchronous callback to return the execution result.

This API is defined but not implemented in OpenHarmony 3.1 Release. It will be available for use in OpenHarmony 3.1 MR.

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
569 570 571 572
| Name     | Type                       | Mandatory  | Description                                      |
| -------- | ------------------------- | ---- | ---------------------------------------- |
| images   | Array&lt;string&gt;       | Yes   | URIs of the images to preview. The value can start with either **https://** or **dataability://**.|
| callback | AsyncCallback&lt;void&gt; | Yes   | Callback used to return the image preview result. If the preview fails, an error message is returned.                       |
W
wusongqing 已提交
573 574 575 576 577 578 579 580

**Example**

  ```
let images = [
    "dataability:///media/external/images/media/50",
    "dataability:///media/external/images/media/55"
];
W
wusongqing 已提交
581
/* Online image usage mode
W
wusongqing 已提交
582 583 584 585
let images = [
    "https://media.xxxx.com/image1.jpg",
    "https://media.xxxx.com/image2.jpg"
];
W
wusongqing 已提交
586
*/
W
wusongqing 已提交
587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608
mediaLibrary.getMediaLibrary().startImagePreview(images, (err) => {
    if (err) {
        console.log("An error occurred when previewing the images.");
        return;
    }
    console.log("Succeeded in previewing the images.");
});
  ```


### startImagePreview

startImagePreview(images: Array&lt;string&gt;, index?: number): Promise&lt;void&gt;

Starts image preview, with the first image to preview specified. This API can be used to preview local images whose URIs start with dataability:// or online images whose URIs start with https://. It uses a promise to return the execution result.

This API is defined but not implemented in OpenHarmony 3.1 Release. It will be available for use in OpenHarmony 3.1 MR.

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
609 610 611 612
| Name   | Type                 | Mandatory  | Description                                      |
| ------ | ------------------- | ---- | ---------------------------------------- |
| images | Array&lt;string&gt; | Yes   | URIs of the images to preview. The value can start with either **https://** or **dataability://**.|
| index  | number              | No   | Index of the first image to preview. If this parameter is not specified, the default value **0** is used.                     |
W
wusongqing 已提交
613 614 615

**Return value**

W
wusongqing 已提交
616 617
| Type                 | Description                             |
| ------------------- | ------------------------------- |
W
wusongqing 已提交
618 619 620 621 622 623 624 625 626
| Promise&lt;void&gt; | Promise used to return the image preview result. If the preview fails, an error message is returned.|

**Example**

  ```
let images = [
    "dataability:///media/external/images/media/50",
    "dataability:///media/external/images/media/55"
];
W
wusongqing 已提交
627
/* Online image usage mode
W
wusongqing 已提交
628 629 630 631
let images = [
    "https://media.xxxx.com/image1.jpg",
    "https://media.xxxx.com/image2.jpg"
];
W
wusongqing 已提交
632
*/
W
wusongqing 已提交
633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653
let index = 1;
mediaLibrary.getMediaLibrary().startImagePreview(images, index).then(() => {
    console.log("Succeeded in previewing the images.");
}).catch((err) => {
    console.log("An error occurred when previewing the images.");
});
  ```


### startMediaSelect

startMediaSelect(option: MediaSelectOption, callback: AsyncCallback&lt;Array&lt;string&gt;&gt;): void

Starts media selection. This API uses an asynchronous callback to return the list of URIs that store the selected media assets.

This API is defined but not implemented in OpenHarmony 3.1 Release. It will be available for use in OpenHarmony 3.1 MR.

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
654 655 656 657
| Name     | Type                                      | Mandatory  | Description                                  |
| -------- | ---------------------------------------- | ---- | ------------------------------------ |
| option   | [MediaSelectOption](#mediaselectoption)  | Yes   | Media selection option.                             |
| callback | AsyncCallback&lt;Array&lt;string&gt;&gt; | Yes   | Callback used to return the list of URIs (starting with **dataability://**) that store the selected media assets.|
W
wusongqing 已提交
658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688

**Example**

  ```
let option = {
    type : "image",
    count : 2
};
mediaLibrary.getMediaLibrary().startMediaSelect(option, (err, value) => {
    if (err) {
        console.log("An error occurred when selecting the media asset.");
        return;
    }
    console.log("Media asset selected.");
    // Obtain the media selection value.
});
  ```


### startMediaSelect

startMediaSelect(option: MediaSelectOption): Promise&lt;Array&lt;string&gt;&gt;

Starts media selection. This API uses a promise to return the list of URIs that store the selected media assets.

This API is defined but not implemented in OpenHarmony 3.1 Release. It will be available for use in OpenHarmony 3.1 MR.

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
689 690 691
| Name   | Type                                     | Mandatory  | Description     |
| ------ | --------------------------------------- | ---- | ------- |
| option | [MediaSelectOption](#mediaselectoption) | Yes   | Media selection option.|
W
wusongqing 已提交
692 693 694

**Return value**

W
wusongqing 已提交
695 696
| Type                                | Description                                      |
| ---------------------------------- | ---------------------------------------- |
W
wusongqing 已提交
697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714
| Promise&lt;Array&lt;string&gt;&gt; | Promise used to return the list of URIs (starting with **dataability://**) that store the selected media assets.|

**Example**

  ```
let option = {
    type : "image",
    count : 2
};
mediaLibrary.getMediaLibrary().startMediaSelect(option).then((value) => {
    console.log("Media asset selected.");
    // Obtain the media selection value.
}).catch((err) => {
    console.log("An error occurred when selecting the media assets.");
});

  ```

W
wusongqing 已提交
715
## FileAsset<sup>7+</sup>
W
wusongqing 已提交
716 717 718 719 720 721 722

Provides APIs for encapsulating file asset attributes.

### Attributes

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

W
wusongqing 已提交
723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745
| Name                     | Type                    | Readable| Writable| Description                                                  |
| ------------------------- | ------------------------ | ---- | ---- | ------------------------------------------------------ |
| id                        | number                   | Yes  | No  | File asset ID.                                          |
| uri                       | string                   | Yes  | No  | File asset URI, for example, dataability:///media/image/2.        |
| mimeType                  | string                   | Yes  | No  | Extended file attributes.                                          |
| mediaType<sup>8+</sup>    | [MediaType](#mediatype8) | Yes  | No  | Media type.                                              |
| displayName               | string                   | Yes  | Yes  | Display file name, including the file name extension.                                |
| title                     | string                   | Yes  | Yes  | Title in the file.                                              |
| relativePath<sup>8+</sup> | string                   | Yes  | Yes  | Relative public directory of the file.                                      |
| parent<sup>8+</sup>       | number                   | Yes  | No  | Parent directory ID.                                              |
| size                      | number                   | Yes  | No  | File size, in bytes.                                |
| dateAdded                 | number                   | Yes  | No  | Date when the file was added. (The value is the number of seconds elapsed since the Epoch time.)        |
| dateModified              | number                   | Yes  | No  | Date when the file was modified. (The value is the number of seconds elapsed since the Epoch time.)        |
| dateTaken                 | number                   | Yes  | No  | Date when the file (photo) was taken. (The value is the number of seconds elapsed since the Epoch time.)        |
| artist<sup>8+</sup>       | string                   | Yes  | No  | Artist of the file.                                                  |
| audioAlbum<sup>8+</sup>   | string                   | Yes  | No  | Audio album.                                                  |
| width                     | number                   | Yes  | No  | Image width, in pixels.                                |
| height                    | number                   | Yes  | No  | Image height, in pixels.                                |
| orientation               | number                   | Yes  | Yes  | Image display direction (clockwise rotation angle, for example, 0, 90, or 180, in degrees).|
| duration<sup>8+</sup>     | number                   | Yes  | No  | Duration, in seconds.                                  |
| albumId                   | number                   | Yes  | No  | ID of the album to which the file belongs.                                  |
| albumUri<sup>8+</sup>     | string                   | Yes  | No  | URI of the album to which the file belongs.                                     |
| albumName                 | string                   | Yes  | No  | Name of the album to which the file belongs.                                    |
W
wusongqing 已提交
746 747 748 749 750 751 752 753 754 755 756 757 758 759


### isDirectory<sup>8+</sup>

isDirectory(callback: AsyncCallback&lt;boolean&gt;): void

Checks whether this file asset is a directory. This API uses an asynchronous callback to return the result.

**Required permissions**: ohos.permission.READ_MEDIA

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
760 761 762
| Name     | Type                          | Mandatory  | Description                 |
| -------- | ---------------------------- | ---- | ------------------- |
| callback | AsyncCallback&lt;boolean&gt; | Yes   | Callback used to return whether the file asset is a directory.|
W
wusongqing 已提交
763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794

**Example**

```
async function example() {
    let imageType = mediaLibrary.MediaType.IMAGE;
    let getImageOp = {
      selections: fileKeyObj.MEDIA_TYPE + '= ?',
      selectionArgs: [imageType.toString()],
      order: fileKeyObj.DATE_ADDED + " DESC",
      extendArgs: "",
    };
    const fetchFileResult = await media.getFileAssets(getImageOp);
    const asset = await fetchFileResult.getFirstObject();
    asset.isDirectory((err, isDirectory) => {
        // do something
    });
}
```

### isDirectory<sup>8+</sup>

isDirectory():Promise&lt;boolean&gt;

Checks whether this file asset is a directory. This API uses a promise to return the result.

**Required permissions**: ohos.permission.READ_MEDIA

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Return value**

W
wusongqing 已提交
795 796
| Type                    | Description                          |
| ---------------------- | ---------------------------- |
W
wusongqing 已提交
797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831
| Promise&lt;boolean&gt; | Promise used to return whether the file asset is a directory.|

**Example**

```
async function example() {
    let imageType = mediaLibrary.MediaType.IMAGE;
    let getImageOp = {
      selections: fileKeyObj.MEDIA_TYPE + '= ?',
      selectionArgs: [imageType.toString()],
      order: fileKeyObj.DATE_ADDED + " DESC",
      extendArgs: "",
    };
    const fetchFileResult = await media.getFileAssets(getImageOp);
    const asset = await fetchFileResult.getFirstObject();
    asset.isDirectory().then(function(isDirectory){
        console.info("isDirectory result:"+ isDirectory);
    }).catch(function(err){
        console.info("isDirectory failed with error:"+ err);
    });
}
```

### commitModify<sup>8+</sup>

commitModify(callback: AsyncCallback&lt;void&gt;): void

Commits the modification of this file asset to the database. This API uses an asynchronous callback to return the result.

**Required permissions**: ohos.permission.READ_MEDIA and ohos.permission.WRITE_MEDIA

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
832 833 834
| Name     | Type                       | Mandatory  | Description   |
| -------- | ------------------------- | ---- | ----- |
| callback | AsyncCallback&lt;void&gt; | Yes   | Void callback.|
W
wusongqing 已提交
835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867

**Example**

```
async function example() {
    let imageType = mediaLibrary.MediaType.IMAGE;
    let getImageOp = {
      selections: fileKeyObj.MEDIA_TYPE + '= ?',
      selectionArgs: [imageType.toString()],
      order: fileKeyObj.DATE_ADDED + " DESC",
      extendArgs: "",
    };
    const fetchFileResult = await media.getFileAssets(getImageOp);
    const asset = await fetchFileResult.getFirstObject();
    asset.title = 'newtitle';
    asset.commitModify(() => {
        console.info('commitModify success');   
    });
}
```

### commitModify<sup>8+</sup>

commitModify(): Promise&lt;void&gt;

Commits the modification of this file asset to the database. This API uses a promise to return the result.

**Required permissions**: ohos.permission.READ_MEDIA and ohos.permission.WRITE_MEDIA

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Return value**

W
wusongqing 已提交
868 869
| Type                 | Description        |
| ------------------- | ---------- |
W
wusongqing 已提交
870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901
| Promise&lt;void&gt; | Void promise.|

**Example**

```
async function example() {
    let imageType = mediaLibrary.MediaType.IMAGE;
    let getImageOp = {
      selections: fileKeyObj.MEDIA_TYPE + '= ?',
      selectionArgs: [imageType.toString()],
      order: fileKeyObj.DATE_ADDED + " DESC",
      extendArgs: "",
    };
    const fetchFileResult = await media.getFileAssets(getImageOp);
    const asset = await fetchFileResult.getFirstObject();
    asset.title = 'newtitle';
    asset.commitModify();
}
```

### open<sup>8+</sup>

open(mode: string, callback: AsyncCallback&lt;number&gt;): void

Opens this file asset. This API uses an asynchronous callback to return the result.

**Required permissions**: ohos.permission.READ_MEDIA (when **mode** is set to **r**) and ohos.permission.WRITE_MEDIA (when **mode** is set to **w**)

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
902 903 904 905
| Name     | Type                         | Mandatory  | Description                                 |
| -------- | --------------------------- | ---- | ----------------------------------- |
| mode     | string                      | Yes   | Mode of opening the file, for example, **r** (read-only), **w** (write-only), and **rw** (read-write).|
| callback | AsyncCallback&lt;number&gt; | Yes   | Callback used to return the file handle.                           |
W
wusongqing 已提交
906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936

**Example**

```
async function example() {
    let mediaType = mediaLibrary.MediaType.IMAGE;
    let DIR_IMAGE = mediaLibrary.DirectoryType.DIR_IMAGE;
    const path = await media.getPublicDirectory(DIR_IMAGE);
    asset = await media.createAsset(mediaType, "image00003.jpg", path);
    asset.open('rw', (openError, fd) => {
            if(fd > 0){
                asset.close(fd);
            }else{
                console.info('File Open Failed!' + openError);
            }
    });
}
```

### open<sup>8+</sup>

open(mode: string): Promise&lt;number&gt;

Opens this file asset. This API uses a promise to return the result.

**Required permissions**: ohos.permission.READ_MEDIA (when **mode** is set to **r**) and ohos.permission.WRITE_MEDIA (when **mode** is set to **w**)

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
937 938 939
| Name | Type    | Mandatory  | Description                                 |
| ---- | ------ | ---- | ----------------------------------- |
| mode | string | Yes   | Mode of opening the file, for example, **r** (read-only), **w** (write-only), and **rw** (read-write).|
W
wusongqing 已提交
940 941 942

**Return value**

W
wusongqing 已提交
943 944
| Type                   | Description           |
| --------------------- | ------------- |
W
wusongqing 已提交
945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976
| Promise&lt;number&gt; | Promise used to return the file handle.|

**Example**

```
async function example() {
    let mediaType = mediaLibrary.MediaType.IMAGE;
    let DIR_IMAGE = mediaLibrary.DirectoryType.DIR_IMAGE;
    const path = await media.getPublicDirectory(DIR_IMAGE);
    asset = await media.createAsset(mediaType, "image00003.jpg", path);
    asset.open('rw')
        .then((fd) => {
            console.info('File fd!' + fd);
        })
        .catch((err) => {
            console.info('File err!' + err);
        });
}
```

### close<sup>8+</sup>

close(fd: number, callback: AsyncCallback&lt;void&gt;): void

Closes this file asset. This API uses an asynchronous callback to return the result.

**Required permissions**: ohos.permission.READ_MEDIA ('r' enabled) and ohos.permission.WRITE_MEDIA ('w' enabled)

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
977 978 979 980
| Name     | Type                       | Mandatory  | Description   |
| -------- | ------------------------- | ---- | ----- |
| fd       | number                    | Yes   | File descriptor.|
| callback | AsyncCallback&lt;void&gt; | Yes   | Void callback.|
W
wusongqing 已提交
981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017

**Example**

```
async function example() {
    let imageType = mediaLibrary.MediaType.IMAGE;
    let getImageOp = {
      selections: fileKeyObj.MEDIA_TYPE + '= ?',
      selectionArgs: [imageType.toString()],
      order: fileKeyObj.DATE_ADDED + " DESC",
      extendArgs: "",
    };
    const fetchFileResult = await media.getFileAssets(getImageOp);
    const asset = await fetchFileResult.getFirstObject();
    asset.close(fd, (closeErr) => {
        if (closeErr != undefined) {
            console.info('mediaLibraryTest : close : FAIL ' + closeErr.message);
            console.info('mediaLibraryTest : ASSET_CALLBACK : FAIL');
        } else {
            console.info("=======asset.close success====>");
        }
    });
}
```

### close<sup>8+</sup>

close(fd: number): Promise&lt;void&gt;

Closes this file asset. This API uses a promise to return the result.

**Required permissions**: ohos.permission.READ_MEDIA ('r' enabled) and ohos.permission.WRITE_MEDIA ('w' enabled)

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
1018 1019 1020
| Name | Type    | Mandatory  | Description   |
| ---- | ------ | ---- | ----- |
| fd   | number | Yes   | File descriptor.|
W
wusongqing 已提交
1021 1022 1023

**Return value**

W
wusongqing 已提交
1024 1025
| Type                 | Description        |
| ------------------- | ---------- |
W
wusongqing 已提交
1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064
| Promise&lt;void&gt; | Void promise.|

**Example**

```
async function example() {
    let imageType = mediaLibrary.MediaType.IMAGE;
    let getImageOp = {
      selections: fileKeyObj.MEDIA_TYPE + '= ?',
      selectionArgs: [imageType.toString()],
      order: fileKeyObj.DATE_ADDED + " DESC",
      extendArgs: "",
    };
    const fetchFileResult = await media.getFileAssets(getImageOp);
    const asset = await fetchFileResult.getFirstObject();
    asset.close(fd).then((closeErr) => {
        if (closeErr != undefined) {
            console.info('mediaLibraryTest : close : FAIL ' + closeErr.message);
            console.info('mediaLibraryTest : ASSET_CALLBACK : FAIL');

        } else {
            console.info("=======asset.close success====>");
        }
    });
}
```

### getThumbnail<sup>8+</sup>

getThumbnail(callback: AsyncCallback&lt;image.PixelMap&gt;): void

Obtains the thumbnail of this file asset. This API uses an asynchronous callback to return the result.

**Required permissions**: ohos.permission.READ_MEDIA

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
1065 1066 1067
| Name     | Type                                 | Mandatory  | Description              |
| -------- | ----------------------------------- | ---- | ---------------- |
| callback | AsyncCallback&lt;image.PixelMap&gt; | Yes   | Callback used to return the pixel map of the thumbnail.|
W
wusongqing 已提交
1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099

**Example**

```
async function example() {
    let imageType = mediaLibrary.MediaType.IMAGE;
    let getImageOp = {
      selections: fileKeyObj.MEDIA_TYPE + '= ?',
      selectionArgs: [imageType.toString()],
      order: fileKeyObj.DATE_ADDED + " DESC",
      extendArgs: "",
    };
    const fetchFileResult = await media.getFileAssets(getImageOp);
    const asset = await fetchFileResult.getFirstObject();
    asset.getThumbnail((err, pixelmap) => {
        console.info('mediaLibraryTest : getThumbnail Successfull '+ pixelmap);
    });
}
```

### getThumbnail<sup>8+</sup>

getThumbnail(size: Size, callback: AsyncCallback&lt;image.PixelMap&gt;): void

Obtains the thumbnail of this file asset, with the thumbnail size passed. This API uses an asynchronous callback to return the result.

**Required permissions**: ohos.permission.READ_MEDIA

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
1100 1101 1102 1103
| Name     | Type                                 | Mandatory  | Description              |
| -------- | ----------------------------------- | ---- | ---------------- |
| size     | [Size](#size8)                      | Yes   | Size of the thumbnail.           |
| callback | AsyncCallback&lt;image.PixelMap&gt; | Yes   | Callback used to return the pixel map of the thumbnail.|
W
wusongqing 已提交
1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135

**Example**

```
async function example() {
    let imageType = mediaLibrary.MediaType.IMAGE;
    let getImageOp = {
      selections: fileKeyObj.MEDIA_TYPE + '= ?',
      selectionArgs: [imageType.toString()],
      order: fileKeyObj.DATE_ADDED + " DESC",
      extendArgs: "",
    };
    const fetchFileResult = await media.getFileAssets(getImageOp);
    const asset = await fetchFileResult.getFirstObject();
    asset.getThumbnail(size, (err, pixelmap) => {
        console.info('mediaLibraryTest : getThumbnail Successfull '+ pixelmap);
    });
}
```

### getThumbnail<sup>8+</sup>

getThumbnail(size?: Size): Promise&lt;image.PixelMap&gt;

Obtains the thumbnail of this file asset, with the thumbnail size passed. This API uses a promise to return the result.

**Required permissions**: ohos.permission.READ_MEDIA

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
1136 1137 1138
| Name | Type            | Mandatory  | Description   |
| ---- | -------------- | ---- | ----- |
| size | [Size](#size8) | No   | Size of the thumbnail.|
W
wusongqing 已提交
1139 1140 1141

**Return value**

W
wusongqing 已提交
1142 1143
| Type                           | Description                   |
| ----------------------------- | --------------------- |
W
wusongqing 已提交
1144 1145 1146 1147 1148 1149 1150 1151
| Promise&lt;image.PixelMap&gt; | Promise to return the pixel map of the thumbnail.|

**Example**

```
async function example() {
    let imageType = mediaLibrary.MediaType.IMAGE;
    let getImageOp = {
W
wusongqing 已提交
1152 1153 1154 1155
        selections: fileKeyObj.MEDIA_TYPE + '= ?',
        selectionArgs: [imageType.toString()],
        order: fileKeyObj.DATE_ADDED + " DESC",
        extendArgs: "",
W
wusongqing 已提交
1156 1157 1158
    };
    const fetchFileResult = await media.getFileAssets(getImageOp);
    const asset = await fetchFileResult.getFirstObject();
W
wusongqing 已提交
1159 1160
    asset.getThumbnail(size)
    .then((pixelmap) => {
W
wusongqing 已提交
1161
        console.info('mediaLibraryTest : getThumbnail Successfull '+ pixelmap);
W
wusongqing 已提交
1162 1163 1164
    })
    .catch((err) => {
        console.info('mediaLibraryTest : getThumbnail fail'+ err);
W
wusongqing 已提交
1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180
    });
}
```

### favorite<sup>8+</sup>

favorite(isFavorite: boolean, callback: AsyncCallback&lt;void&gt;): void

Favorites or unfavorites this file asset. This API uses an asynchronous callback to return the result.

**Required permissions**: ohos.permission.READ_MEDIA and ohos.permission.WRITE_MEDIA

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
1181 1182 1183 1184
| Name       | Type                       | Mandatory  | Description                                |
| ---------- | ------------------------- | ---- | ---------------------------------- |
| isFavorite | boolean                   | Yes   | Whether to favorite or unfavorite the file. The value **true** means to favorite the file, and **false** means to unfavorite the file.|
| callback   | AsyncCallback&lt;void&gt; | Yes   | Void callback.                             |
W
wusongqing 已提交
1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216

**Example**

```
async function example() {
    let imageType = mediaLibrary.MediaType.IMAGE;
    let getImageOp = {
      selections: fileKeyObj.MEDIA_TYPE + '= ?',
      selectionArgs: [imageType.toString()],
      order: fileKeyObj.DATE_ADDED + " DESC",
      extendArgs: "",
    };
    const fetchFileResult = await media.getFileAssets(getImageOp);
    const asset = await fetchFileResult.getFirstObject();
    asset.favorite(true,function(err){
        // do something
    });
}
```

### favorite<sup>8+</sup>

favorite(isFavorite: boolean): Promise&lt;void&gt;

Favorites or unfavorites this file asset. This API uses a promise to return the result.

**Required permissions**: ohos.permission.READ_MEDIA and ohos.permission.WRITE_MEDIA

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
1217 1218 1219
| Name       | Type     | Mandatory  | Description                                |
| ---------- | ------- | ---- | ---------------------------------- |
| isFavorite | boolean | Yes   | Whether to favorite or unfavorite the file. The value **true** means to favorite the file, and **false** means to unfavorite the file.|
W
wusongqing 已提交
1220 1221 1222

**Return value**

W
wusongqing 已提交
1223 1224
| Type                 | Description        |
| ------------------- | ---------- |
W
wusongqing 已提交
1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259
| Promise&lt;void&gt; | Void promise.|

**Example**

```
async function example() {
    let imageType = mediaLibrary.MediaType.IMAGE;
    let getImageOp = {
      selections: fileKeyObj.MEDIA_TYPE + '= ?',
      selectionArgs: [imageType.toString()],
      order: fileKeyObj.DATE_ADDED + " DESC",
      extendArgs: "",
    };
    const fetchFileResult = await media.getFileAssets(getImageOp);
    const asset = await fetchFileResult.getFirstObject();
    asset.favorite(true).then(function() {
        console.info("favorite successfully");
    }).catch(function(err){
        console.info("favorite failed with error:"+ err);
    });
}
```

### isFavorite<sup>8+</sup>

isFavorite(callback: AsyncCallback&lt;boolean&gt;): void

Checks whether this file asset is favorited. This API uses an asynchronous callback to return the result.

**Required permissions**: ohos.permission.READ_MEDIA

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
1260 1261 1262
| Name     | Type                          | Mandatory  | Description         |
| -------- | ---------------------------- | ---- | ----------- |
| callback | AsyncCallback&lt;boolean&gt; | Yes   | Callback used to return whether the file asset is favorited.|
W
wusongqing 已提交
1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298

**Example**

```
async function example() {
    let imageType = mediaLibrary.MediaType.IMAGE;
    let getImageOp = {
      selections: fileKeyObj.MEDIA_TYPE + '= ?',
      selectionArgs: [imageType.toString()],
      order: fileKeyObj.DATE_ADDED + " DESC",
      extendArgs: "",
    };
    const fetchFileResult = await media.getFileAssets(getImageOp);
    const asset = await fetchFileResult.getFirstObject();
    asset.isFavorite((err, isFavorite) => {
        if (isFavorite) {
            console.info('FileAsset is favorite');
        }else{
            console.info('FileAsset is not favorite');
        }
    });
}
```

### isFavorite<sup>8+</sup>

isFavorite():Promise&lt;boolean&gt;

Checks whether this file asset is favorited. This API uses a promise to return the result.

**Required permissions**: ohos.permission.READ_MEDIA

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Return value**

W
wusongqing 已提交
1299 1300
| Type                    | Description                |
| ---------------------- | ------------------ |
W
wusongqing 已提交
1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337
| Promise&lt;boolean&gt; | Promise used to return whether the file asset is favorited.|

**Example**

```
async function example() {
    let imageType = mediaLibrary.MediaType.IMAGE;
    let getImageOp = {
      selections: fileKeyObj.MEDIA_TYPE + '= ?',
      selectionArgs: [imageType.toString()],
      order: fileKeyObj.DATE_ADDED + " DESC",
      extendArgs: "",
    };
    const fetchFileResult = await media.getFileAssets(getImageOp);
    const asset = await fetchFileResult.getFirstObject();
    asset.isFavorite().then(function(isFavorite){
        console.info("isFavorite result:"+ isFavorite);
    }).catch(function(err){
        console.info("isFavorite failed with error:"+ err);
    });
}
```

### trash<sup>8+</sup>

trash(isTrash: boolean, callback: AsyncCallback&lt;void&gt;): void

Moves this file asset to the trash. This API uses an asynchronous callback to return the result.

Files in the trash are not actually deleted. You can set **isTrash** to **false** to restore the files from the trash.

**Required permissions**: ohos.permission.READ_MEDIA and ohos.permission.WRITE_MEDIA

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
1338 1339 1340 1341
| Name     | Type                       | Mandatory  | Description       |
| -------- | ------------------------- | ---- | --------- |
| isTrash  | boolean                   | Yes   | Whether to move the file asset to the trash. The value **true** means to move the file asset to the trash, and **false** means the opposite.|
| callback | AsyncCallback&lt;void&gt; | Yes   | Void callback.    |
W
wusongqing 已提交
1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376

**Example**

```
async function example() {
    let imageType = mediaLibrary.MediaType.IMAGE;
    let getImageOp = {
      selections: fileKeyObj.MEDIA_TYPE + '= ?',
      selectionArgs: [imageType.toString()],
      order: fileKeyObj.DATE_ADDED + " DESC",
      extendArgs: "",
    };
    const fetchFileResult = await media.getFileAssets(getImageOp);
    const asset = await fetchFileResult.getFirstObject();
    asset.trash(true, trashCallBack);
    function trashCallBack(err, trash) {
        console.info('mediaLibraryTest : ASSET_CALLBACK ASSET_CALLBACK trash');
    }
}
```

### trash<sup>8+</sup>

trash(isTrash: boolean): Promise&lt;void&gt;

Moves this file asset to the trash. This API uses a promise to return the result.

Files in the trash are not actually deleted. You can set **isTrash** to **false** to restore the files from the trash.

**Required permissions**: ohos.permission.READ_MEDIA and ohos.permission.WRITE_MEDIA

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
1377 1378 1379
| Name    | Type     | Mandatory  | Description       |
| ------- | ------- | ---- | --------- |
| isTrash | boolean | Yes   | Whether to move the file asset to the trash. The value **true** means to move the file asset to the trash, and **false** means the opposite.|
W
wusongqing 已提交
1380 1381 1382

**Return value**

W
wusongqing 已提交
1383 1384
| Type                 | Description        |
| ------------------- | ---------- |
W
wusongqing 已提交
1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419
| Promise&lt;void&gt; | Void promise.|

**Example**

```
async function example() {
    let imageType = mediaLibrary.MediaType.IMAGE;
    let getImageOp = {
      selections: fileKeyObj.MEDIA_TYPE + '= ?',
      selectionArgs: [imageType.toString()],
      order: fileKeyObj.DATE_ADDED + " DESC",
      extendArgs: "",
    };
    const fetchFileResult = await media.getFileAssets(getImageOp);
    const asset = await fetchFileResult.getFirstObject();
    asset.trash(true).then(function() {
        console.info("trash successfully");
    }).catch(function(err){
        console.info("trash failed with error:"+ err);
    });
}
```

### isTrash<sup>8+</sup>

isTrash(callback: AsyncCallback&lt;boolean&gt;): void

Checks whether this file asset is in the trash. This API uses an asynchronous callback to return the result.

**Required permissions**: ohos.permission.READ_MEDIA

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
1420 1421 1422
| Name     | Type                          | Mandatory  | Description             |
| -------- | ---------------------------- | ---- | --------------- |
| callback | AsyncCallback&lt;boolean&gt; | Yes   | Callback used to return whether the file asset is in the trash. If the file asset is in the trash, **true** will be returned; otherwise, **false** will be returned.|
W
wusongqing 已提交
1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463

**Example**

```
async function example() {
    let imageType = mediaLibrary.MediaType.IMAGE;
    let getImageOp = {
      selections: fileKeyObj.MEDIA_TYPE + '= ?',
      selectionArgs: [imageType.toString()],
      order: fileKeyObj.DATE_ADDED + " DESC",
      extendArgs: "",
    };
    const fetchFileResult = await media.getFileAssets(getImageOp);
    const asset = await fetchFileResult.getFirstObject();
    asset.isTrash(isTrashCallBack);
    function isTrashCallBack(err, isTrash) {
            if (isTrash == true) {
                console.info('mediaLibraryTest : ASSET_CALLBACK ASSET_CALLBACK isTrash = ' + isTrash);
                asset.trash(true, trashCallBack);

            } else {
                console.info('mediaLibraryTest : ASSET_CALLBACK isTrash Unsuccessfull = ' + err);
                console.info('mediaLibraryTest : ASSET_CALLBACK isTrash : FAIL');

            }
    }
}
```

### isTrash<sup>8+</sup>

isTrash():Promise&lt;boolean&gt;

Checks whether this file asset is in the trash. This API uses a promise to return the result.

**Required permissions**: ohos.permission.READ_MEDIA

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Return value**

W
wusongqing 已提交
1464 1465
| Type                 | Description                  |
| ------------------- | -------------------- |
W
wusongqing 已提交
1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488
| Promise&lt;void&gt; | Promise used to return whether the file asset is in the trash. If the file asset is in the trash, **true** will be returned; otherwise, **false** will be returned.|

**Example**

```
async function example() {
    let imageType = mediaLibrary.MediaType.IMAGE;
    let getImageOp = {
      selections: fileKeyObj.MEDIA_TYPE + '= ?',
      selectionArgs: [imageType.toString()],
      order: fileKeyObj.DATE_ADDED + " DESC",
      extendArgs: "",
    };
    const fetchFileResult = await media.getFileAssets(getImageOp);
    const asset = await fetchFileResult.getFirstObject();
    asset.isTrash().then(function(isTrash){
        console.info("isTrash result:"+ isTrash);
    }).catch(function(err){
        console.info("isTrash failed with error:"+ err);
    });
}
```

W
wusongqing 已提交
1489
## FetchFileResult<sup>7+</sup>
W
wusongqing 已提交
1490 1491 1492

Implements the result set of the file retrieval operation.

W
wusongqing 已提交
1493
### getCount<sup>7+</sup>
W
wusongqing 已提交
1494 1495 1496 1497 1498 1499 1500 1501 1502

getCount(): number

Obtains the total number of files in the result set.

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Return value**

W
wusongqing 已提交
1503 1504
| Type    | Description      |
| ------ | -------- |
W
wusongqing 已提交
1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521
| number | Total number of files.|

**Example**

```
async function example() {
    let getFileCountOneOp = {
        selections: fileKeyObj.MEDIA_TYPE + '= ?',
        selectionArgs: [fileType.toString()],
        order: fileKeyObj.DATE_ADDED + " DESC",
        extendArgs: "",
    };
    let fetchFileResult = await media.getFileAssets(getFileCountOneOp);
    const fetchCount = fetchFileResult.getCount();
}
```

W
wusongqing 已提交
1522
### isAfterLast<sup>7+</sup>
W
wusongqing 已提交
1523 1524 1525 1526 1527 1528 1529 1530 1531

isAfterLast(): boolean

Checks whether the cursor is in the last row of the result set.

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Return value**

W
wusongqing 已提交
1532 1533
| Type     | Description                                |
| ------- | ---------------------------------- |
W
wusongqing 已提交
1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564
| boolean | Returns **true** if the cursor is in the last row of the result set; returns *false** otherwise.|

**Example**

```
async function example() {
    let imageType = mediaLibrary.MediaType.IMAGE;
    let getImageOp = {
      selections: fileKeyObj.MEDIA_TYPE + '= ?',
      selectionArgs: [imageType.toString()],
      order: fileKeyObj.DATE_ADDED + " DESC",
      extendArgs: "",
    };
    let fetchFileResult = await media.getFileAssets(getImageOp);
    const fetchCount = fetchFileResult.getCount();
    console.info('mediaLibraryTest : count:' + fetchCount);
    let fileAsset = await fetchFileResult.getFirstObject();
    for (var i = 1; i < fetchCount; i++) {
            fileAsset = await fetchFileResult.getNextObject();
            if(i == fetchCount - 1) {
              console.info('mediaLibraryTest : isLast');
              var result = fetchFileResult.isAfterLast();
              console.info('mediaLibraryTest : isAfterLast:' + result);
              console.info('mediaLibraryTest : isAfterLast end');
              fetchFileResult.close();

            }
    }
}
```

W
wusongqing 已提交
1565
### close<sup>7+</sup>
W
wusongqing 已提交
1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588

close(): void

Releases and invalidates this **FetchFileResult** instance. Other APIs cannot be invoked after the instance is released.

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Example**

```
async function example() {
    let imageType = mediaLibrary.MediaType.IMAGE;
    let getImageOp = {
      selections: fileKeyObj.MEDIA_TYPE + '= ?',
      selectionArgs: [imageType.toString()],
      order: fileKeyObj.DATE_ADDED + " DESC",
      extendArgs: "",
    };
    let fetchFileResult = await media.getFileAssets(getImageOp);
    fetchFileResult.close();
}
```

W
wusongqing 已提交
1589
### getFirstObject<sup>7+</sup>
W
wusongqing 已提交
1590 1591 1592 1593 1594 1595 1596 1597 1598

getFirstObject(callback: AsyncCallback&lt;FileAsset&gt;): void

Obtains the first file asset in the result set. This API uses an asynchronous callback to return the result.

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
1599 1600 1601
| Name  | Type                                         | Mandatory| Description                                       |
| -------- | --------------------------------------------- | ---- | ------------------------------------------- |
| callback | AsyncCallback&lt;[FileAsset](#fileasset7)&gt; | Yes  | Callback used to return the first file asset.|
W
wusongqing 已提交
1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624

**Example**

```
async function example() {
    let imageType = mediaLibrary.MediaType.IMAGE;
    let getImageOp = {
      selections: fileKeyObj.MEDIA_TYPE + '= ?',
      selectionArgs: [imageType.toString()],
      order: fileKeyObj.DATE_ADDED + " DESC",
      extendArgs: "",
    };
    let fetchFileResult = await media.getFileAssets(getImageOp);
    fetchFileResult.getFirstObject((err, value) => {
       if (err) {
           console.error('Failed ');
           return;
       }
       console.log(value);
    })
}
```

W
wusongqing 已提交
1625
### getFirstObject<sup>7+</sup>
W
wusongqing 已提交
1626 1627 1628 1629 1630 1631 1632 1633 1634

getFirstObject(): Promise&lt;FileAsset&gt;

Obtains the first file asset in the result set. This API uses a promise to return the result.

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Return value**

W
wusongqing 已提交
1635 1636 1637
| Type                                   | Description                      |
| --------------------------------------- | -------------------------- |
| Promise&lt;[FileAsset](#fileasset7)&gt; | Promise used to return the file asset.|
W
wusongqing 已提交
1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658

**Example**

```
async function example() {
    let imageType = mediaLibrary.MediaType.IMAGE;
    let getImageOp = {
      selections: fileKeyObj.MEDIA_TYPE + '= ?',
      selectionArgs: [imageType.toString()],
      order: fileKeyObj.DATE_ADDED + " DESC",
      extendArgs: "",
    };
    let fetchFileResult = await media.getFileAssets(getImageOp);
    fetchFileResult.getFirstObject().then(function(fileAsset){
        console.info("getFirstObject successfully:"+ JSON.stringify(fileAsset));
    }).catch(function(err){
        console.info("getFirstObject failed with error:"+ err);
    });
}
```

W
wusongqing 已提交
1659
### getNextObject<sup>7+</sup>
W
wusongqing 已提交
1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670

 getNextObject(callback: AsyncCallback&lt;FileAsset&gt;): void

Obtains the next file asset in the result set. This API uses an asynchronous callback to return the result.

**Required permissions**: ohos.permission.READ_MEDIA

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
1671 1672 1673
| Name   | Type                                         | Mandatory| Description                                     |
| --------- | --------------------------------------------- | ---- | ----------------------------------------- |
| callbacke | AsyncCallback&lt;[FileAsset](#fileasset7)&gt; | Yes  | Callback used to return the next file asset.|
W
wusongqing 已提交
1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696

**Example**

```
async function example() {
    let imageType = mediaLibrary.MediaType.IMAGE;
    let getImageOp = {
      selections: fileKeyObj.MEDIA_TYPE + '= ?',
      selectionArgs: [imageType.toString()],
      order: fileKeyObj.DATE_ADDED + " DESC",
      extendArgs: "",
    };
    let fetchFileResult = await media.getFileAssets(getImageOp);
    fetchFileResult.getNextObject((err, value) => {
       if (err) {
           console.error('Failed ');
           return;
       }
       console.log(value);
    })
}
```

W
wusongqing 已提交
1697
### getNextObject<sup>7+</sup>
W
wusongqing 已提交
1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708

 getNextObject(): Promise&lt;FileAsset&gt;

Obtains the next file asset in the result set. This API uses a promise to return the result.

**Required permissions**: ohos.permission.READ_MEDIA

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Return value**

W
wusongqing 已提交
1709 1710 1711
| Type                                   | Description             |
| --------------------------------------- | ----------------- |
| Promise&lt;[FileAsset](#fileasset7)&gt; | Promise used to return the next file asset.|
W
wusongqing 已提交
1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730

**Example**

```
async function example() {
    let imageType = mediaLibrary.MediaType.IMAGE;
    let getImageOp = {
      selections: fileKeyObj.MEDIA_TYPE + '= ?',
      selectionArgs: [imageType.toString()],
      order: fileKeyObj.DATE_ADDED + " DESC",
      extendArgs: "",
    };
    let fetchFileResult = await media.getFileAssets(getImageOp);
    const fetchCount = fetchFileResult.getCount();
    console.info('mediaLibraryTest : count:' + fetchCount);
    fileAsset = await fetchFileResult.getNextObject();
}
```

W
wusongqing 已提交
1731
### getLastObject<sup>7+</sup>
W
wusongqing 已提交
1732 1733 1734 1735 1736 1737 1738 1739 1740

getLastObject(callback: AsyncCallback&lt;FileAsset&gt;): void

Obtains the last file asset in the result set. This API uses an asynchronous callback to return the result.

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
1741 1742 1743
| Name  | Type                                         | Mandatory| Description                       |
| -------- | --------------------------------------------- | ---- | --------------------------- |
| callback | AsyncCallback&lt;[FileAsset](#fileasset7)&gt; | Yes  | Callback used to return the last file asset.|
W
wusongqing 已提交
1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766

**Example**

```
async function example() {
    let imageType = mediaLibrary.MediaType.IMAGE;
    let getImageOp = {
      selections: fileKeyObj.MEDIA_TYPE + '= ?',
      selectionArgs: [imageType.toString()],
      order: fileKeyObj.DATE_ADDED + " DESC",
      extendArgs: "",
    };
    let fetchFileResult = await media.getFileAssets(getImageOp);
    fetchFileResult.getLastObject((err, value) => {
       if (err) {
           console.error('Failed ');
           return;
       }
       console.log(value);
    })
}
```

W
wusongqing 已提交
1767
### getLastObject<sup>7+</sup>
W
wusongqing 已提交
1768 1769 1770 1771 1772 1773 1774 1775 1776

getLastObject(): Promise&lt;FileAsset&gt;

Obtains the last file asset in the result set. This API uses a promise to return the result.

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Return value**

W
wusongqing 已提交
1777 1778 1779
| Type                                   | Description             |
| --------------------------------------- | ----------------- |
| Promise&lt;[FileAsset](#fileasset7)&gt; | Promise used to return the next file asset.|
W
wusongqing 已提交
1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796

**Example**

```
async function example() {
    let imageType = mediaLibrary.MediaType.IMAGE;
    let getImageOp = {
      selections: fileKeyObj.MEDIA_TYPE + '= ?',
      selectionArgs: [imageType.toString()],
      order: fileKeyObj.DATE_ADDED + " DESC",
      extendArgs: "",
    };
    let fetchFileResult = await media.getFileAssets(getImageOp);
    let lastObject = await fetchFileResult.getLastObject();
}
```

W
wusongqing 已提交
1797
### getPositionObject<sup>7+</sup>
W
wusongqing 已提交
1798 1799 1800 1801 1802 1803 1804 1805 1806

getPositionObject(index: number, callback: AsyncCallback&lt;FileAsset&gt;): void

Obtains a file asset with the specified index in the result set. This API uses an asynchronous callback to return the result.

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
1807 1808 1809
| Name      | Type                                      | Mandatory  | Description                |
| -------- | ---------------------------------------- | ---- | ------------------ |
| index    | number                                   | Yes   | Index of the file asset to obtain. The value starts from **0**.    |
W
wusongqing 已提交
1810
| callback | AsyncCallback&lt;[FileAsset](#fileasset7)&gt; | Yes   | Callback used to return the last file asset.|
W
wusongqing 已提交
1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833

**Example**

```
async function example() {
    let imageType = mediaLibrary.MediaType.IMAGE;
    let getImageOp = {
      selections: fileKeyObj.MEDIA_TYPE + '= ?',
      selectionArgs: [imageType.toString()],
      order: fileKeyObj.DATE_ADDED + " DESC",
      extendArgs: "",
    };
    let fetchFileResult = await media.getFileAssets(getImageOp);
    fetchFileResult.getPositionObject(0, (err, value) => {
       if (err) {
           console.error('Failed ');
           return;
       }
       console.log(value);
    })
}
```

W
wusongqing 已提交
1834
### getPositionObject<sup>7+</sup>
W
wusongqing 已提交
1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845

getPositionObject(index: number): Promise&lt;FileAsset&gt;

Obtains a file asset with the specified index in the result set. This API uses a promise to return the result.

**Required permissions**: ohos.permission.READ_MEDIA

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
1846 1847 1848
| Name   | Type    | Mandatory  | Description            |
| ----- | ------ | ---- | -------------- |
| index | number | Yes   | Index of the file asset to obtain. The value starts from **0**.|
W
wusongqing 已提交
1849 1850 1851

**Return value**

W
wusongqing 已提交
1852 1853 1854
| Type                                   | Description             |
| --------------------------------------- | ----------------- |
| Promise&lt;[FileAsset](#fileasset7)&gt; | Promise used to return the next file asset.|
W
wusongqing 已提交
1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877

**Example**

```
async function example() {
    let imageType = mediaLibrary.MediaType.IMAGE;
    let getImageOp = {
      selections: fileKeyObj.MEDIA_TYPE + '= ?',
      selectionArgs: [imageType.toString()],
      order: fileKeyObj.DATE_ADDED + " DESC",
      extendArgs: "",
    };
    let fetchFileResult = await media.getFileAssets(getImageOp);
    fetchFileResult.getPositionObject(1, (err, value) => {
       if (err) {
           console.error('Failed ');
           return;
       }
       console.log(value);
    })
}
```

W
wusongqing 已提交
1878
### getAllObject<sup>7+</sup>
W
wusongqing 已提交
1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889

getAllObject(callback: AsyncCallback&lt;Array&lt;FileAsset&gt;&gt;): void

Obtains all the file assets in the result set. This API uses an asynchronous callback to return the result.

**Required permissions**: ohos.permission.READ_MEDIA

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
1890 1891
| Name      | Type                                      | Mandatory  | Description                  |
| -------- | ---------------------------------------- | ---- | -------------------- |
W
wusongqing 已提交
1892
| callback | AsyncCallback<Array<[FileAsset](#fileasset7)>> | Yes   | Callback used to return the file assets.|
W
wusongqing 已提交
1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915

**Example**

```
async function example() {
    let imageType = mediaLibrary.MediaType.IMAGE;
    let getImageOp = {
      selections: fileKeyObj.MEDIA_TYPE + '= ?',
      selectionArgs: [imageType.toString()],
      order: fileKeyObj.DATE_ADDED + " DESC",
      extendArgs: "",
    };
    let fetchFileResult = await media.getFileAssets(getImageOp);
    fetchFileResult.getAllObject((err, value) => {
       if (err) {
           console.error('Failed ');
           return;
       }
       console.log(value);
    })
}
```

W
wusongqing 已提交
1916
### getAllObject<sup>7+</sup>
W
wusongqing 已提交
1917 1918 1919 1920 1921 1922 1923 1924 1925

getAllObject(): Promise&lt;Array&lt;FileAsset&gt;&gt;

Obtains all the file assets in the result set. This API uses a promise to return the result.

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Return value**

W
wusongqing 已提交
1926 1927 1928
| Type                                    | Description                 |
| ---------------------------------------- | --------------------- |
| Promise<Array<[FileAsset](#fileasset7)>> | Promise used to return the file assets.|
W
wusongqing 已提交
1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945

**Example**

```
async function example() {
    let imageType = mediaLibrary.MediaType.IMAGE;
    let getImageOp = {
      selections: fileKeyObj.MEDIA_TYPE + '= ?',
      selectionArgs: [imageType.toString()],
      order: fileKeyObj.DATE_ADDED + " DESC",
      extendArgs: "",
    };
    let fetchFileResult = await media.getFileAssets(getImageOp);
    var data = fetchFileResult.getAllObject();
}
```

W
wusongqing 已提交
1946
## Album<sup>7+</sup>
W
wusongqing 已提交
1947 1948 1949 1950 1951 1952 1953

Provides APIs to implement a physical album.

### **Attributes**

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

W
wusongqing 已提交
1954 1955
| Name          | Type   | Readable  | Writable  | Description     |
| ------------ | ------ | ---- | ---- | ------- |
W
wusongqing 已提交
1956 1957 1958
| albumId | number | Yes   | No   | Album ID.   |
| albumName | string | Yes   | Yes   | Album name.   |
| albumUri<sup>8+</sup> | string | Yes   | No   | Album URI.  |
W
wusongqing 已提交
1959
| dateModified | number | Yes   | No   | Date when the album was modified.   |
W
wusongqing 已提交
1960 1961 1962
| count<sup>8+</sup> | number | Yes   | No   | Number of files in the album.|
| relativePath<sup>8+</sup> | string | Yes   | No   | Relative path of the album.   |
| coverUri<sup>8+</sup> | string | Yes   | No   | URI of the cover file of the album.|
W
wusongqing 已提交
1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975

### commitModify<sup>8+</sup>

commitModify(callback: AsyncCallback&lt;void&gt;): void

Commits the modification of the album attributes to the database. This API uses an asynchronous callback to return the result.

**Required permissions**: ohos.permission.READ_MEDIA and ohos.permission.WRITE_MEDIA

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
1976 1977 1978
| Name  | Type                     | Mandatory| Description      |
| -------- | ------------------------- | ---- | ---------- |
| callback | AsyncCallback&lt;void&gt; | Yes  | Void callback.|
W
wusongqing 已提交
1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012

**Example**

```
async function example() {
    let AlbumNoArgsfetchOp = {
        selections: '',
        selectionArgs: [],
    };
    const albumList = await media.getAlbums(AlbumNoArgsfetchOp);
    const album = albumList[0];
    album.albumName = 'hello';
    album.commitModify((err) => {
       if (err) {
           console.error('Failed ');
           return;
       }
       console.log('Modify successful.');
    })
}
```

### commitModify<sup>8+</sup>

commitModify(): Promise&lt;void&gt;

Commits the modification of the album attributes to the database. This API uses a promise to return the result.

**Required permissions**: ohos.permission.READ_MEDIA and ohos.permission.WRITE_MEDIA

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Return value**

W
wusongqing 已提交
2013 2014
| Type                 | Description          |
| ------------------- | ------------ |
W
wusongqing 已提交
2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035
| Promise&lt;void&gt; | Void promise.|

**Example**

```
async function example() {
    let AlbumNoArgsfetchOp = {
        selections: '',
        selectionArgs: [],
    };
    const albumList = await media.getAlbums(AlbumNoArgsfetchOp);
    const album = albumList[0];
    album.albumName = 'hello';
    album.commitModify().then(function() {
        console.info("commitModify successfully");
    }).catch(function(err){
        console.info("commitModify failed with error:"+ err);
    });
}
```

W
wusongqing 已提交
2036
### getFileAssets<sup>7+</sup>
W
wusongqing 已提交
2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047

getFileAssets(options: MediaFetchOptions, callback: AsyncCallback&lt;FetchFileResult&gt;): void

Obtains the file assets in this album. This API uses an asynchronous callback to return the result.

**Required permissions**: ohos.permission.READ_MEDIA

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
2048 2049 2050 2051
| Name  | Type                                               | Mandatory| Description                               |
| -------- | --------------------------------------------------- | ---- | ----------------------------------- |
| options  | [MediaFetchOptions](#mediafetchoptions7)            | Yes  | Options for fetching the files.                     |
| callback | AsyncCallback<[FetchFileResult](#fetchfileresult7)> | Yes  | Callback used to return the file assets.|
W
wusongqing 已提交
2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069

**Example**

```
async function example() {
    let AlbumNoArgsfetchOp = {
        selections: '',
        selectionArgs: [],
    };
    const albumList = await media.getAlbums(AlbumNoArgsfetchOp);
    const album = albumList[0];
    album.getFileAssets(fileNoArgsfetchOp, getFileAssetsCallBack);
    function getFileAssetsCallBack(err, fetchFileResult) {
        // do something
    }
}
```

W
wusongqing 已提交
2070
### getFileAssets<sup>7+</sup>
W
wusongqing 已提交
2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081

 getFileAssets(options?: MediaFetchOptions): Promise&lt;FetchFileResult&gt;

Obtains the file assets in this album. This API uses a promise to return the result.

**Required permissions**: ohos.permission.READ_MEDIA

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

**Parameters**

W
wusongqing 已提交
2082 2083 2084
| Name | Type                                    | Mandatory| Description          |
| ------- | ---------------------------------------- | ---- | -------------- |
| options | [MediaFetchOptions](#mediafetchoptions7) | No  | Options for fetching the files.|
W
wusongqing 已提交
2085 2086 2087

**Return value**

W
wusongqing 已提交
2088 2089 2090
| Type                                         | Description                     |
| --------------------------------------------- | ------------------------- |
| Promise<[FetchFileResult](#fetchfileresult7)> | Promise used to return the file assets.|
W
wusongqing 已提交
2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115

**Example**

```
async function example() {
    let AlbumNoArgsfetchOp = {
        selections: '',
        selectionArgs: [],
    };
    const albumList = await media.getAlbums(AlbumNoArgsfetchOp);
    const album = albumList[0];
    album.getFileAssets(fileNoArgsfetchOp).then(function(albumFetchFileResult){
        console.info("getFileAssets successfully:"+ JSON.stringify(albumFetchFileResult));
    }).catch(function(err){
        console.info("getFileAssets failed with error:"+ err);
    });
}
```

## PeerInfo<sup>8+</sup>

Describes information about a registered device.

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

W
wusongqing 已提交
2116 2117 2118 2119 2120 2121
| Name      | Type                      | Readable| Writable| Description            |
| ---------- | -------------------------- | ---- | ---- | ---------------- |
| deviceName | string                     | Yes  | No  | Name of the registered device.  |
| networkId  | string                     | Yes  | No  | Network ID of the registered device.|
| deviceType | [DeviceType](#devicetype8) | Yes  | No  | Type of the registered device.        |
| isOnline   | boolean                    | Yes  | No  | Whether the registered device is online.        |
W
wusongqing 已提交
2122 2123 2124



W
wusongqing 已提交
2125
## MediaType<sup>8+</sup>
W
wusongqing 已提交
2126 2127 2128 2129 2130

Enumerates media types.

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

W
wusongqing 已提交
2131 2132 2133 2134 2135 2136
| Name | Default Value | Description|
| ----- | ------ | ---- |
| FILE  | 1      | File.|
| IMAGE | 3      | Image.|
| VIDEO | 4      | Video.|
| AUDIO | 5      | Audio.|
W
wusongqing 已提交
2137

W
wusongqing 已提交
2138
## FileKey<sup>8+</sup>
W
wusongqing 已提交
2139 2140 2141 2142 2143

Enumerates key file information.

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

W
wusongqing 已提交
2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161
| Name         | Default Value              | Description                                                      |
| ------------- | ------------------- | ---------------------------------------------------------- |
| ID            | file_id             | File ID.                                                  |
| RELATIVE_PATH | relative_path       | Relative public directory of the file.                                          |
| DISPLAY_NAME  | display_name        | Display file name.                                                  |
| PARENT        | parent              | Parent directory ID.                                                  |
| MIME_TYPE     | mime_type           | Extended file attributes.                                              |
| MEDIA_TYPE    | media_type          | Media type.                                                  |
| SIZE          | size                | File size, in bytes.                                    |
| DATE_ADDED    | date_added          | Date when the file was added. (The value is the number of seconds elapsed since the Epoch time.)            |
| DATE_MODIFIED | date_modified       | Date when the file was modified. (The value is the number of seconds elapsed since the Epoch time.)            |
| DATE_TAKEN    | date_taken          | Date when the file (photo) was taken. (The value is the number of seconds elapsed since the Epoch time.)            |
| TITLE         | title               | Title in the file.                                                  |
| ARTIST        | artist              | Artist of the file.                                                      |
| AUDIOALBUM    | audio_album         | Audio album.                                                      |
| DURATION      | duration            | Duration, in seconds.                                      |
| WIDTH         | width               | Image width, in pixels.                                    |
| HEIGHT        | height              | Image height, in pixels.                                    |
W
wusongqing 已提交
2162
| ORIENTATION   | orientation         | Image display direction (clockwise rotation angle, for example, 0, 90, and 180, in degrees).|
W
wusongqing 已提交
2163 2164
| ALBUM_ID      | bucket_id           | ID of the album to which the file belongs.                                      |
| ALBUM_NAME    | bucket_display_name | Name of the album to which the file belongs.                                        |
W
wusongqing 已提交
2165

W
wusongqing 已提交
2166
## DirectoryType<sup>8+</sup>
W
wusongqing 已提交
2167 2168 2169 2170 2171

Enumerates directory types.

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

W
wusongqing 已提交
2172 2173 2174 2175 2176 2177 2178 2179
| Name         | Default Value | Description              |
| ------------- | ------ | ------------------ |
| DIR_CAMERA    | 0      | Directory of camera files.|
| DIR_VIDEO     | 1      | Directory of video files.      |
| DIR_IMAGE     | 2      | Directory of image files.      |
| DIR_AUDIO     | 3      | Directory of audio files.      |
| DIR_DOCUMENTS | 4      | Directory of documents.      |
| DIR_DOWNLOAD  | 5      | Download directory.      |
W
wusongqing 已提交
2180

W
wusongqing 已提交
2181
## DeviceType<sup>8+</sup>
W
wusongqing 已提交
2182 2183 2184 2185 2186

Enumerates device types.

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

W
wusongqing 已提交
2187 2188 2189 2190 2191 2192 2193 2194 2195
| Name        | Default Value | Description      |
| ------------ | ------ | ---------- |
| TYPE_UNKNOWN | 0      | Unknown.|
| TYPE_LAPTOP  | 1      | Laptop.|
| TYPE_PHONE   | 2      | Phone.      |
| TYPE_TABLET  | 3      | Tablet.  |
| TYPE_WATCH   | 4      | Smart watch.  |
| TYPE_CAR     | 5      | Vehicle-mounted device.  |
| TYPE_TV      | 6      | TV.  |
W
wusongqing 已提交
2196

W
wusongqing 已提交
2197
## MediaFetchOptions<sup>7+</sup>
W
wusongqing 已提交
2198 2199 2200 2201 2202

Describes options for fetching media files.

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

W
wusongqing 已提交
2203 2204 2205 2206 2207 2208 2209 2210
| Name                   | Type               | Readable| Writable| Mandatory| Description                                                        |
| ----------------------- | ------------------- | ---- | ---- | ---- | ------------------------------------------------------------ |
| selections              | string              | Yes  | Yes  | Yes  | Conditions for fetching files. The enumerated values in [FileKey](#filekey8) are used as the column names of the conditions. Example:<br>selections: mediaLibrary.FileKey.MEDIA_TYPE + '= ? OR' +mediaLibrary.FileKey.MEDIA_TYPE + '= ?',|
| selectionArgs           | Array&lt;string&gt; | Yes  | Yes  | Yes  | Value of the condition, which corresponds to the value of the condition column in **selections**.<br>Example:<br>selectionArgs: [mediaLibrary.MediaType.IMAGE.toString(), mediaLibrary.MediaType.VIDEO.toString()], |
| order<sup>8+</sup>      | string              | Yes  | Yes  | No  | Sorting mode of the search results, which can be ascending or descending. The enumerated values in [FileKey](#filekey8) are used as the columns for sorting the search results. Example:<br>Ascending: order: mediaLibrary.FileKey.DATE_ADDED + " AESC"<br>Descending: order: mediaLibrary.FileKey.DATE_ADDED + " DESC"|
| uri<sup>8+</sup>        | string              | Yes  | Yes  | No  | File URI.                                                     |
| networkId<sup>8+</sup>  | string              | Yes  | Yes  | No  | Network ID of the registered device.                                              |
| extendArgs<sup>8+</sup> | string              | Yes  | Yes  | No  | Extended parameters for fetching the files. Currently, no extended parameters are available.                        |
W
wusongqing 已提交
2211 2212 2213 2214 2215

## Size<sup>8+</sup>

Describes the image size.

W
wusongqing 已提交
2216 2217 2218 2219
| Name    | Type    | Readable  | Writable  | Description      |
| ------ | ------ | ---- | ---- | -------- |
| width  | number | Yes   | Yes   | Image width, in pixels.|
| height | number | Yes   | Yes   | Image height, in pixels.|
W
wusongqing 已提交
2220 2221 2222 2223 2224 2225 2226 2227 2228 2229

## MediaAssetOption

Implements the media asset option.

This API is defined but not implemented in OpenHarmony 3.1 Release. It will be available for use in OpenHarmony 3.1 MR.

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core


W
wusongqing 已提交
2230 2231 2232 2233 2234
| Name          | Type    | Mandatory  | Description                                      |
| ------------ | ------ | ---- | ---------------------------------------- |
| src          | string | Yes   | URI of the media library.                              |
| mimeType     | string | Yes   | Multipurpose Internet Mail Extensions (MIME) type of the media.<br>Example: 'image/\*' and 'video/\*'.|
| relativePath | string | No   | Custom path for storing media assets. If this parameter is unspecified, media assets are stored in the default path. For example, if you set this parameter to **imageDir/image2/**, the media assets will be stored in **default/imageDir/image2/**, where **default** represents the default path.|
W
wusongqing 已提交
2235 2236 2237 2238 2239 2240 2241 2242 2243

## MediaSelectOption

Describes media selection option.

This API is defined but not implemented in OpenHarmony 3.1 Release. It will be available for use in OpenHarmony 3.1 MR.

**System capability**: SystemCapability.Multimedia.MediaLibrary.Core

W
wusongqing 已提交
2244 2245 2246 2247
| Name   | Type    | Mandatory  | Description                  |
| ----- | ------ | ---- | -------------------- |
| type  | string | Yes   | Media type, which can be **image** and **video**.|
| count | number | Yes   | Maximum number of media assets that can be selected.           |