Update docs against 14231+15161

Signed-off-by: wusongqing<wusongqing@huawei.com>

en/application-dev/file-management/medialibrary-album-guidelines.md

@@ -39,19 +39,19 @@ The following describes how to create an album named **myAlbum**.
 
 ```ts
 async function example() {
-    let mediaType = mediaLibrary.MediaType.IMAGE;
-    let DIR_IMAGE = mediaLibrary.DirectoryType.DIR_IMAGE;
-    const context = getContext(this);
-    let media = mediaLibrary.getMediaLibrary(context);
-    const path = await media.getPublicDirectory(DIR_IMAGE);
-    // myAlbum is the path for storing the new file and the name of the new album.
-    media.createAsset(mediaType, 'test.jpg', path + 'myAlbum/', (err, fileAsset) => {
-        if (fileAsset != undefined) {
-        console.info('createAlbum successfully, message = ' + fileAsset);
-        } else {
-        console.info('createAlbum failed, message = ' + err);
-        }
-    });
+  let mediaType = mediaLibrary.MediaType.IMAGE;
+  let DIR_IMAGE = mediaLibrary.DirectoryType.DIR_IMAGE;
+  const context = getContext(this);
+  let media = mediaLibrary.getMediaLibrary(context);
+  const path = await media.getPublicDirectory(DIR_IMAGE);
+  // myAlbum is the path for storing the new file and the name of the new album.
+  media.createAsset(mediaType, 'test.jpg', path + 'myAlbum/', (err, fileAsset) => {
+    if (fileAsset === undefined) {
+      console.error('createAlbum failed, message = ' + err);
+    } else {
+      console.info('createAlbum successfully, message = ' + JSON.stringify(fileAsset));
+    }
+  });
 }
 ```
 
@@ -75,20 +75,20 @@ The following describes how to rename the album **newAlbum**.
 
 ```ts
 async function example() {
-    let AlbumNoArgsfetchOp = {
-        selections: '',
-        selectionArgs: [],
-    };
-    const context = getContext(this);
-    let media = mediaLibrary.getMediaLibrary(context);
-    let albumList = await media.getAlbums(AlbumNoArgsfetchOp);
-    let album = albumList[0];
-    album.albumName = 'newAlbum';
-    // Void callback.
-    album.commitModify().then(function() {
-        console.info("albumRename successfully");
-    }).catch(function(err){
-        console.info("albumRename failed with error: " + err);
-    });
+  let AlbumNoArgsfetchOp = {
+    selections: '',
+    selectionArgs: [],
+  };
+  const context = getContext(this);
+  let media = mediaLibrary.getMediaLibrary(context);
+  let albumList = await media.getAlbums(AlbumNoArgsfetchOp);
+  let album = albumList[0];
+  album.albumName = 'newAlbum';
+  // Void callback.
+  album.commitModify().then(() => {
+    console.info("albumRename successfully");
+  }).catch((err) => {
+    console.error("albumRename failed with error: " + err);
+  });
 }
 ```

en/application-dev/file-management/medialibrary-filepath-guidelines.md

@@ -37,15 +37,15 @@ The following describes how to obtain the public directory that stores camera fi
 
 ```ts
 async function example(){
-    const context = getContext(this);
-    let media = mediaLibrary.getMediaLibrary(context);
-    let DIR_CAMERA = mediaLibrary.DirectoryType.DIR_CAMERA;
-    const dicResult = await media.getPublicDirectory(DIR_CAMERA);
-    if (dicResult == 'Camera/') {
-        console.info('mediaLibraryTest : getPublicDirectory passed');
-    } else {
-        console.info('mediaLibraryTest : getPublicDirectory failed');
-    }
+  const context = getContext(this);
+  let media = mediaLibrary.getMediaLibrary(context);
+  let DIR_CAMERA = mediaLibrary.DirectoryType.DIR_CAMERA;
+  const dicResult = await media.getPublicDirectory(DIR_CAMERA);
+  if (dicResult == 'Camera/') {
+    console.info('mediaLibraryTest : getPublicDirectory passed');
+  } else {
+    console.error('mediaLibraryTest : getPublicDirectory failed');
+  }
 }
 ```
 
@@ -59,47 +59,52 @@ Users can access files stored in the public directories through the system appli
 
 You can call [mediaLibrary.FileAsset.open](../reference/apis/js-apis-medialibrary.md#open8-1) to open a file in a public directory.
 
-You can call [fileio.open](../reference/apis/js-apis-fileio.md#fileioopen7) to open a file in the application sandbox. The sandbox directory can be accessed only through the application context.
+You can call [fs.open](../reference/apis/js-apis-file-fs.md#fsopen) to open a file in the application sandbox. The sandbox directory can be accessed only through the application context.
 
 **Prerequisites**
 
 - You have obtained a **MediaLibrary** instance.
-- You have granted the permission **ohos.permission.WRITE_MEDIA**.
-- You have imported the module [@ohos.fileio](../reference/apis/js-apis-fileio.md) in addition to @ohos.multimedia.mediaLibrary.
+- You have granted the permissions **ohos.permission.READ_MEDIA** and **ohos.permission.WRITE_MEDIA**.
+- You have imported the module [@ohos.file.fs](../reference/apis/js-apis-file-fs.md) in addition to @ohos.multimedia.mediaLibrary.
+- The **testFile.txt** file has been created and contains content.
 
 **How to Develop**
 
-1. Call [context.filesDir](../reference/apis/js-apis-inner-app-context.md#contextgetfilesdir) to obtain the directory of the application sandbox.
+1. Call [context.filesDir](../reference/apis/js-apis-file-fs.md) to obtain the directory of the application sandbox.
 2. Call **MediaLibrary.getFileAssets** and **FetchFileResult.getFirstObject** to obtain the first file in the result set of the public directory.
-3. Call **fileio.open** to open the file in the sandbox.
+3. Call **fs.open** to open the file in the sandbox.
 4. Call **fileAsset.open** to open the file in the public directory.
-5. Call **fileio.copyfile** to copy the file.
-6. Call **fileAsset.close** and **fileio.close** to close the file.
+5. Call [fs.copyfile](../reference/apis/js-apis-file-fs.md#fscopyfile) to copy the file.
+6. Call **fileAsset.close** and [fs.close](../reference/apis/js-apis-file-fs.md#fsclose) to close the file.
 
 **Example 1: Copying Files from the Public Directory to the Sandbox**
 
 ```ts
 async function copyPublic2Sandbox() {
+  try {
     const context = getContext(this);
     let media = mediaLibrary.getMediaLibrary(context);
-    let sandboxDirPath = globalThis.context.filesDir;
+    let sandboxDirPath = context.filesDir;
     let fileKeyObj = mediaLibrary.FileKey;
     let fileAssetFetchOp = {
-        selections: fileKeyObj.DISPLAY_NAME + '= ?',
-        selectionArgs: ['testFile.txt'],
+      selections: fileKeyObj.DISPLAY_NAME + '= ?',
+      selectionArgs: ['testFile.txt'],
     };
     let fetchResult = await media.getFileAssets(fileAssetFetchOp);
     let fileAsset = await fetchResult.getFirstObject();
 
     let fdPub = await fileAsset.open('rw');
-    let fdSand = await fileio.open(sandboxDirPath + '/testFile.txt', 0o2 | 0o100, 0o666);
-    await fileio.copyFile(fdPub, fdSand);
+    let fdSand = await fs.open(sandboxDirPath + '/testFile.txt', fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE);
+    await fs.copyFile(fdPub, fdSand.fd);
 
     await fileAsset.close(fdPub);
-    await fileio.close(fdSand);
+    await fs.close(fdSand.fd);
 
-    let content_sand = await fileio.readText(sandboxDirPath + '/testFile.txt');
-    console.log('content read from sandbox file: ', content_sand)
+    let content_sand = await fs.readText(sandboxDirPath + '/testFile.txt');
+    console.info('content read from sandbox file: ', content_sand)
+  } catch (err) {
+    console.info('[demo] copyPublic2Sandbox fail, err: ', err);
+  }
 }
 ```
 
@@ -107,81 +112,81 @@ async function copyPublic2Sandbox() {
 
 ```ts
 async function copySandbox2Public() {
-    const context = getContext(this);
-    let media = mediaLibrary.getMediaLibrary(context);
-    let sandboxDirPath = globalThis.context.filesDir;
-
-    let DIR_DOCUMENTS = mediaLibrary.DirectoryType.DIR_DOCUMENTS;
-    const publicDirPath = await media.getPublicDirectory(DIR_DOCUMENTS);
-    try {
-        let fileAsset = await media.createAsset(mediaLibrary.MediaType.FILE, 'testFile02.txt', publicDirPath);
-        console.info('createFile successfully, message = ' + fileAsset);
-    } catch (err) {
-        console.info('createFile failed, message = ' + err);
-    }
-    try {
-        let fileKeyObj = mediaLibrary.FileKey;
-        let fileAssetFetchOp = {
-            selections: fileKeyObj.DISPLAY_NAME + '= ?',
-            selectionArgs: ['testFile02.txt'],
-        };
-        let fetchResult = await media.getFileAssets(fileAssetFetchOp);
-        var fileAsset = await fetchResult.getFirstObject();
-    } catch (err) {
-        console.info('file asset get failed, message = ' + err);
-    }
-    let fdPub = await fileAsset.open('rw');
-    let fdSand = await fileio.open(sandboxDirPath + 'testFile.txt', 0o2);
-    await fileio.copyFile(fdSand, fdPub);
-    await fileio.close(fdPub);
-    await fileio.close(fdSand);
-    let fdPubRead = await fileAsset.open('rw');
-    try {
-        let arrayBuffer = new ArrayBuffer(4096);
-        await fileio.read(fdPubRead, arrayBuffer);
-        var content_pub = String.fromCharCode(...new Uint8Array(arrayBuffer));
-        fileAsset.close(fdPubRead);
-    } catch (err) {
-        console.log('read text failed, message = ', err);
-    }
-    console.log('content read from public file: ', content_pub);
+  const context = getContext(this);
+  let media = mediaLibrary.getMediaLibrary(context);
+  let sandboxDirPath = context.filesDir;
+
+  let DIR_DOCUMENTS = mediaLibrary.DirectoryType.DIR_DOCUMENTS;
+  const publicDirPath = await media.getPublicDirectory(DIR_DOCUMENTS);
+  try {
+    let fileAsset = await media.createAsset(mediaLibrary.MediaType.FILE, 'testFile02.txt', publicDirPath);
+    console.info('createFile successfully, message = ' + fileAsset);
+  } catch (err) {
+    console.error('createFile failed, message = ' + err);
+  }
+  try {
+    let fileKeyObj = mediaLibrary.FileKey;
+    let fileAssetFetchOp = {
+      selections: fileKeyObj.DISPLAY_NAME + '= ?',
+      selectionArgs: ['testFile02.txt'],
+    };
+    let fetchResult = await media.getFileAssets(fileAssetFetchOp);
+    var fileAsset = await fetchResult.getFirstObject();
+  } catch (err) {
+    console.error('file asset get failed, message = ' + err);
+  }
+  let fdPub = await fileAsset.open('rw');
+  let fdSand = await fs.open(sandboxDirPath + 'testFile.txt', OpenMode.READ_WRITE);
+  await fs.copyFile(fdSand.fd, fdPub);
+  await fileAsset.close(fdPub);
+  await fs.close(fdSand.fd);
+  let fdPubRead = await fileAsset.open('rw');
+  try {
+    let arrayBuffer = new ArrayBuffer(4096);
+    await fs.read(fdPubRead, arrayBuffer);
+    var content_pub = String.fromCharCode(...new Uint8Array(arrayBuffer));
+    fileAsset.close(fdPubRead);
+  } catch (err) {
+    console.error('read text failed, message = ', err);
+  }
+  console.info('content read from public file: ', content_pub);
 }
 ```
 
 ### Reading and Writing a File
 
-You can use **FileAsset.open** and **FileAsset.close** of [mediaLibrary](../reference/apis/js-apis-medialibrary.md) to open and close a file, and use **fileio.read** and **fileio.write** of [fileio](../reference/apis/js-apis-fileio.md) to read and write a file.
+You can use **FileAsset.open** and **FileAsset.close** of [mediaLibrary](../reference/apis/js-apis-medialibrary.md) to open and close a file, and use **fs.read** and **fs.write** in [file.fs](../reference/apis/js-apis-file-fs.md) to read and write the file.
 
 **Prerequisites**
 
 - You have obtained a **MediaLibrary** instance.
-- You have granted the permission **ohos.permission.WRITE_MEDIA**.
-- You have imported the module [@ohos.fileio](../reference/apis/js-apis-fileio.md) in addition to @ohos.multimedia.mediaLibrary.
+- You have granted the permissions **ohos.permission.READ_MEDIA** and **ohos.permission.WRITE_MEDIA**.
+- You have imported the module [@ohos.file.fs](../reference/apis/js-apis-file-fs.md) in addition to @ohos.multimedia.mediaLibrary.
 
 **How to Develop**
 
 1. Create a file.
 
-   ```ts
-   async function example() {
-       let mediaType = mediaLibrary.MediaType.FILE;
-       let DIR_DOCUMENTS = mediaLibrary.DirectoryType.DIR_DOCUMENTS;
-       const context = getContext(this);
-       let media = mediaLibrary.getMediaLibrary(context);
-       const path = await media.getPublicDirectory(DIR_DOCUMENTS);
-       media.createAsset(mediaType, "testFile.text", path).then (function (asset) {
-           console.info("createAsset successfully:" + JSON.stringify(asset));
-       }).catch(function(err){
-           console.info("createAsset failed with error: " + err);
-       });
-   }
-   ```
+```ts
+async function example() {
+  let mediaType = mediaLibrary.MediaType.FILE;
+  let DIR_DOCUMENTS = mediaLibrary.DirectoryType.DIR_DOCUMENTS;
+  const context = getContext(this);
+  let media = mediaLibrary.getMediaLibrary(context);
+  const path = await media.getPublicDirectory(DIR_DOCUMENTS);
+  media.createAsset(mediaType, "testFile.text", path).then((asset) => {
+    console.info("createAsset successfully:" + JSON.stringify(asset));
+  }).catch((err) => {
+    console.error("createAsset failed with error: " + err);
+  });
+}
+```
 
 2. Call **FileAsset.open** to open the file.
 
-3. Call **fileio.write** to write a string to the file.
+3. Call [fs.write](../reference/apis/js-apis-file-fs.md#fswrite) to write a string to the file.
 
-4. Call **fileio.read** to read the file and save the data read in an array buffer.
+4. Call [fs.read](../reference/apis/js-apis-file-fs.md#fsread) to read the file and save the data read in an array buffer.
 
 5. Convert the array buffer to a string.
 
@@ -191,25 +196,25 @@ You can use **FileAsset.open** and **FileAsset.close** of [mediaLibrary](../refe
 
 ```ts
 async function writeOnlyPromise() {
-    const context = getContext(this);
-    let media = mediaLibrary.getMediaLibrary(context);
-    let fileKeyObj = mediaLibrary.FileKey;
-    let fileAssetFetchOp = {
-        selections: fileKeyObj.DISPLAY_NAME + '= ?',
-        selectionArgs: ['testFile.txt'],
-    };
-    let fetchResult = await media.getFileAssets(fileAssetFetchOp);
-    let fileAsset = await fetchResult.getFirstObject();
-    console.info('fileAssetName: ', fileAsset.displayName);
-
-    try {
-        let fd = await fileAsset.open('w');
-        console.info('file descriptor: ', fd);
-        await fileio.write(fd, "Write file test content.");
-        await fileAsset.close(fd);
-    } catch (err) {
-        console.info('write file failed, message = ', err);
-    }
+  const context = getContext(this);
+  let media = mediaLibrary.getMediaLibrary(context);
+  let fileKeyObj = mediaLibrary.FileKey;
+  let fileAssetFetchOp = {
+    selections: fileKeyObj.DISPLAY_NAME + '= ?',
+    selectionArgs: ['testFile.txt'],
+  };
+  let fetchResult = await media.getFileAssets(fileAssetFetchOp);
+  let fileAsset = await fetchResult.getFirstObject();
+  console.info('fileAssetName: ', fileAsset.displayName);
+
+  try {
+    let fd = await fileAsset.open('w');
+    console.info('file descriptor: ', fd);
+    await fs.write(fd, "Write file test content.");
+    await fileAsset.close(fd);
+  } catch (err) {
+    console.error('write file failed, message = ', err);
+  }
 }
 ```
 
@@ -217,28 +222,28 @@ async function writeOnlyPromise() {
 
 ```ts
 async function readOnlyPromise() {
-    const context = getContext(this);
-    let media = mediaLibrary.getMediaLibrary(context);
-    let fileKeyObj = mediaLibrary.FileKey;
-    let fileAssetFetchOp = {
-        selections: fileKeyObj.DISPLAY_NAME + '= ?' ,
-        selectionArgs: ['testFile.txt'],
-    };
-    let fetchResult = await media.getFileAssets(fileAssetFetchOp);
-    let fileAsset = await fetchResult.getFirstObject();
-    console.info('fileAssetName: ', fileAsset.displayName);
-
-    try {
-        let fd = await fileAsset.open('r');
-        let arrayBuffer = new ArrayBuffer(4096);
-        await fileio.read(fd, arrayBuffer);
-        let fileContent = String.fromCharCode(...new Uint8Array(arrayBuffer));
-        globalThis.fileContent = fileContent;
-        globalThis.fileName = fileAsset.displayName;
-        console.info('file content: ', fileContent);
-        await fileAsset.close(fd);
-    } catch (err) {
-        console.info('read file failed, message = ', err);
-    }
+  const context = getContext(this);
+  let media = mediaLibrary.getMediaLibrary(context);
+  let fileKeyObj = mediaLibrary.FileKey;
+  let fileAssetFetchOp = {
+    selections: fileKeyObj.DISPLAY_NAME + '= ?' ,
+    selectionArgs: ['testFile.txt'],
+  };
+  let fetchResult = await media.getFileAssets(fileAssetFetchOp);
+  let fileAsset = await fetchResult.getFirstObject();
+  console.info('fileAssetName: ', fileAsset.displayName);
+
+  try {
+    let fd = await fileAsset.open('r');
+    let arrayBuffer = new ArrayBuffer(4096);
+    await fs.read(fd, arrayBuffer);
+    let fileContent = String.fromCharCode(...new Uint8Array(arrayBuffer));
+    globalThis.fileContent = fileContent;
+    globalThis.fileName = fileAsset.displayName;
+    console.info('file content: ', fileContent);
+    await fileAsset.close(fd);
+  } catch (err) {
+    console.error('read file failed, message = ', err);
+  }
 }
 ```

en/application-dev/file-management/medialibrary-overview.md

@@ -64,64 +64,64 @@ After configuring the permissions in the **module.json5** file, the application
 
 1. Declare the permissions in the **module.json5** file. Add the **requestPermissions** tag under **module** in the file, and set the tag based on the project requirements. For details about the tag, see [Guide for Requesting Permissions from User](../security/accesstoken-guidelines.md).
 
-   ```json
-   {
-       "module": {
-           "requestPermissions": [
-               {
-                   "name": "ohos.permission.MEDIA_LOCATION",
-                   "reason": "$string:reason",
-                   "usedScene": {
-                       "abilities": [
-                         "EntryAbility"
-                       ],
-                       "when": "always"
-               }
-               },
-               {
-                   "name": "ohos.permission.READ_MEDIA",
-                   "reason": "$string:reason",
-                   "usedScene": {
-                       "abilities": [
-                           "EntryAbility"
-                       ],
-                       "when": "always"
-                   }
-               },
-               {
-                   "name": "ohos.permission.WRITE_MEDIA",
-                   "reason": "$string:reason",
-                   "usedScene": {
-                       "abilities": [
-                           "EntryAbility"
-                       ],
-                       "when": "always"
-                   }
-               }
-           ]
-       }
-   }    
-   ```
+```json
+{
+  "module": {
+    "requestPermissions": [
+      {
+        "name": "ohos.permission.MEDIA_LOCATION",
+        "reason": "$string:reason",
+        "usedScene": {
+          "abilities": [
+            "EntryAbility"
+          ],
+          "when": "always"
+        }
+      },
+      {
+        "name": "ohos.permission.READ_MEDIA",
+        "reason": "$string:reason",
+        "usedScene": {
+          "abilities": [
+            "EntryAbility"
+          ],
+          "when": "always"
+        }
+      },
+      {
+        "name": "ohos.permission.WRITE_MEDIA",
+        "reason": "$string:reason",
+        "usedScene": {
+          "abilities": [
+            "EntryAbility"
+          ],
+          "when": "always"
+        }
+      }
+    ]
+  }
+}    
+```
 
 2. In the **Ability.ts** file, call **requestPermissionsFromUser** in the **onWindowStageCreate** callback to check for the required permissions and if they are not granted, request the permissions from the user by displaying a dialog box.
 
-   ```ts
-   import UIAbility from '@ohos.app.ability.UIAbility';
-   import abilityAccessCtrl, {Permissions} from '@ohos.abilityAccessCtrl';
-   
-   export default class EntryAbility extends UIAbility {
-       onWindowStageCreate(windowStage) {
-           let list : Array<Permissions> = ['ohos.permission.READ_MEDIA', 'ohos.permission.WRITE_MEDIA'];
-           let permissionRequestResult;
-           let atManager = abilityAccessCtrl.createAtManager();
-           atManager.requestPermissionsFromUser(this.context, list, (err, result) => {
-               if (err) {
-                   console.log('requestPermissionsFromUserError: ' + JSON.stringify(err));
-               } else {
-                   permissionRequestResult=result;
-                   console.log('permissionRequestResult: ' + JSON.stringify(permissionRequestResult));
-               }    
-           });       
-       }
-   }
-   ```
+```ts
+import UIAbility from '@ohos.app.ability.UIAbility';
+import abilityAccessCtrl, {Permissions} from '@ohos.abilityAccessCtrl';
+
+export default class EntryAbility extends UIAbility {
+  onWindowStageCreate(windowStage) {
+    let list : Array<Permissions> = ['ohos.permission.READ_MEDIA', 'ohos.permission.WRITE_MEDIA'];
+    let permissionRequestResult;
+    let atManager = abilityAccessCtrl.createAtManager();
+    atManager.requestPermissionsFromUser(this.context, list, (err, result) => {
+      if (err) {
+        console.error('requestPermissionsFromUserError: ' + JSON.stringify(err));
+      } else {
+        permissionRequestResult = result;
+        console.info('permissionRequestResult: ' + JSON.stringify(permissionRequestResult));
+      }
+    });       
+  }
+}
+```

en/application-dev/file-management/medialibrary-resource-guidelines.md

@@ -33,30 +33,33 @@ To specify the image as the media type, set **selectionArgs** to **MediaType.IMA
 
 ```ts
 async function example() {
-    let fileKeyObj = mediaLibrary.FileKey;
-    let fileType = mediaLibrary.MediaType.IMAGE;
-    let option = {
-        selections: fileKeyObj.MEDIA_TYPE + '= ?',
-        selectionArgs: [fileType.toString()],
-    };
-    const context = getContext(this);
-    let media = mediaLibrary.getMediaLibrary(context);
-    const fetchFileResult = await media.getFileAssets(option);
-    for (let i = 0; i < fetchFileResult.getCount(); i++) {
-        fetchFileResult.getNextObject((err, fileAsset) => {
-        if (err) {
-            console.error('Failed ');
-            return;
-        }
-        console.log('fileAsset.displayName ' + i + ': ' + fileAsset.displayName);
-        })
-    } 
+  let fileKeyObj = mediaLibrary.FileKey;
+  let fileType = mediaLibrary.MediaType.IMAGE;
+  let option = {
+    selections: fileKeyObj.MEDIA_TYPE + '= ?',
+    selectionArgs: [fileType.toString()],
+  };
+  const context = getContext(this);
+  let media = mediaLibrary.getMediaLibrary(context);
+  const fetchFileResult = await media.getFileAssets(option);
+  fetchFileResult.getFirstObject().then((fileAsset) => {
+    console.log('getFirstObject.displayName : ' + fileAsset.displayName);
+    for (let i = 1; i < fetchFileResult.getCount(); i++) {
+      fetchFileResult.getNextObject().then((fileAsset) => {
+        console.info('fileAsset.displayName ' + i + ': ' + fileAsset.displayName);
+      }).catch((err) => {
+        console.error('Failed to get next object: ' + err);
+      });
+    }
+  }).catch((err) => {
+    console.error('Failed to get first object: ' + err);
+  });
 }
 ```
 
 ### Querying Media Assets with the Specified Date
 
-The following describes how to obtain media assets that are added on the specified date. You can also use the modification date and shooting date as the retrieval conditions.
+The following describes how to obtain all the media assets that are added from the specified date. You can also use the modification date and shooting date as the retrieval conditions.
 
 To specify the date when the files are added as the retrieval condition, set **selections** to **FileKey.DATE_ADDED**.
 
@@ -64,23 +67,26 @@ To specify the date 2022-8-5, set **selectionArgs** to **2022-8-5**.
 
 ```ts
 async function example() {
-    let fileKeyObj = mediaLibrary.FileKey;
-    let option = {
-        selections: fileKeyObj.DATE_ADDED + '= ?',
-        selectionArgs: ['2022-8-5'],
-    };
-    const context = getContext(this);
-    let media = mediaLibrary.getMediaLibrary(context);
-    const fetchFileResult = await media.getFileAssets(option);
-    for (let i = 0; i < fetchFileResult.getCount(); i++) {
-        fetchFileResult.getNextObject((err, fileAsset) => {
-        if (err) {
-            console.error('Failed ');
-            return;
-        }
-        console.log('fileAsset.displayName ' + i + ': ' + fileAsset.displayName);
-        })
-    } 
+  let fileKeyObj = mediaLibrary.FileKey;
+  let option = {
+    selections: fileKeyObj.DATE_ADDED + '> ?',
+    selectionArgs: ['2022-8-5'],
+  };
+  const context = getContext(this);
+  let media = mediaLibrary.getMediaLibrary(context);
+  const fetchFileResult = await media.getFileAssets(option);
+  fetchFileResult.getFirstObject().then((fileAsset) => {
+    console.info('getFirstObject.displayName : ' + fileAsset.displayName);
+    for (let i = 1; i < fetchFileResult.getCount(); i++) {
+      fetchFileResult.getNextObject().then((fileAsset) => {
+        console.info('fileAsset.displayName ' + i + ': ' + fileAsset.displayName);
+      }).catch((err) => {
+        console.error('Failed to get next object: ' + err);
+      });
+    }
+  }).catch((err) => {
+    console.error('Failed to get first object: ' + err);
+  });
 }
 ```
 
@@ -92,25 +98,28 @@ To sort files in descending order by the date when they are added, set **order**
 
 ```ts
 async function example() {
-    let fileKeyObj = mediaLibrary.FileKey;
-    let fileType = mediaLibrary.MediaType.IMAGE;
-    let option = {
-        selections: fileKeyObj.MEDIA_TYPE + '= ?',
-        selectionArgs: [fileType.toString()],
-        order: fileKeyObj.DATE_ADDED + " DESC",
-    };
-    const context = getContext(this);
-    let media = mediaLibrary.getMediaLibrary(context);
-    const fetchFileResult = await media.getFileAssets(option);
-    for (let i = 0; i < fetchFileResult.getCount(); i++) {
-        fetchFileResult.getNextObject((err, fileAsset) => {
-        if (err) {
-            console.error('Failed ');
-            return;
-        }
-        console.log('fileAsset.displayName ' + i + ': ' + fileAsset.displayName);
-        })
-    } 
+  let fileKeyObj = mediaLibrary.FileKey;
+  let fileType = mediaLibrary.MediaType.IMAGE;
+  let option = {
+    selections: fileKeyObj.MEDIA_TYPE + '= ?',
+    selectionArgs: [fileType.toString()],
+    order: fileKeyObj.DATE_ADDED + " DESC",
+  };
+  const context = getContext(this);
+  let media = mediaLibrary.getMediaLibrary(context);
+  const fetchFileResult = await media.getFileAssets(option);
+  fetchFileResult.getFirstObject().then((fileAsset) => {
+    console.info('getFirstObject.displayName : ' + fileAsset.displayName);
+    for (let i = 1; i < fetchFileResult.getCount(); i++) {
+      fetchFileResult.getNextObject().then((fileAsset) => {
+        console.info('fileAsset.displayName ' + i + ': ' + fileAsset.displayName);
+      }).catch((err) => {
+        console.error('Failed to get next object: ' + err);
+      });
+    }
+  }).catch((err) => {
+    console.error('Failed to get first object: ' + err);
+  });
 }
 ```
 
@@ -124,31 +133,29 @@ To specify the album name **'myAlbum'**, set **selectionArgs** to **'myAlbum'**.
 
 ```ts
 async function example() {
-    let fileKeyObj = mediaLibrary.FileKey;
-    let fileType = mediaLibrary.MediaType.IMAGE;
-    let option = {
-        selections: fileKeyObj.ALBUM_NAME + '= ?',
-        selectionArgs: ['myAlbum'],
-    };
-    const context = getContext(this);
-    let media = mediaLibrary.getMediaLibrary(context);
-    const fetchFileResult = await media.getFileAssets(option);
-    for (let i = 0; i < fetchFileResult.getCount(); i++) {
-        fetchFileResult.getNextObject((err, fileAsset) => {
-        if (err) {
-            console.error('Failed ');
-            return;
-        }
-        console.log('fileAsset.displayName ' + i + ': ' + fileAsset.displayName);
-        })
-    } 
+  let fileKeyObj = mediaLibrary.FileKey;
+  let option = {
+    selections: fileKeyObj.ALBUM_NAME + '= ?',
+    selectionArgs: ['myAlbum'],
+  };
+  const context = getContext(this);
+  let media = mediaLibrary.getMediaLibrary(context);
+  const fetchFileResult = await media.getFileAssets(option);
+  if (albumList.length > 0) {
+    fetchFileResult.getFirstObject().then((album) => {
+      console.info('getFirstObject.displayName : ' + album.albumName);
+    }).catch((err) => {
+      console.error('Failed to get first object: ' + err);
+    });
+  } else {
+    console.info('getAlbum list is: 0');
+  }
 }
 ```
 
 ## Obtaining Images and Videos in an Album
 
 You can obtain media assets in an album in either of the following ways:
-
 - Call [MediaLibrary.getFileAssets](../reference/apis/js-apis-medialibrary.md#getfileassets7-1) with an album specified, as described in [Querying Media Assets with the Specfied Album Name](#querying-media-assets-with-the-specified-album-name).
 - Call [Album.getFileAssets](../reference/apis/js-apis-medialibrary.md#getfileassets7-3) to obtain an **Album** instance, so as to obtain the media assets in it.
 
@@ -163,24 +170,24 @@ The following describes how to obtain videos in an album named **New Album 1**.
 
 1. Create a retrieval condition for obtaining the target **Album** instance.
 
-   ```ts
-   let fileKeyObj = mediaLibrary.FileKey;
-   let AlbumNoArgsFetchOp = {
-       selections: fileKeyObj.ALBUM_NAME + '= ?',
-       selectionArgs:['New Album 1']
-   }
-   ```
+```ts
+let fileKeyObj = mediaLibrary.FileKey;
+let AlbumNoArgsFetchOp = {
+  selections: fileKeyObj.ALBUM_NAME + '= ?',
+  selectionArgs:['New Album 1']
+}
+```
 
 2. Create a retrieval condition for obtaining videos in the target album.
 
-   ```ts
-   let fileKeyObj = mediaLibrary.FileKey;
-   let imageType = mediaLibrary.MediaType.VIDEO;
-   let imagesFetchOp  = {
-       selections: fileKeyObj.MEDIA_TYPE + '= ?',
-       selectionArgs: [imageType.toString()],
-   }
-   ```
+```ts
+let fileKeyObj = mediaLibrary.FileKey;
+let videoType = mediaLibrary.MediaType.VIDEO;
+let videoFetchOp  = {
+  selections: fileKeyObj.MEDIA_TYPE + '= ?',
+  selectionArgs: [videoType.toString()],
+}
+```
 
 3. Call **Album.getFileAssets** to obtain the videos in the target album.
 
@@ -188,28 +195,28 @@ Complete sample code:
 
 ```ts
 async function getCameraImagePromise() {
-    const context = getContext(this);
-    let media = mediaLibrary.getMediaLibrary(context);
-    let fileKeyObj = mediaLibrary.FileKey;
-    let imageType = mediaLibrary.MediaType.IMAGE;
-    let imagesFetchOp = {
-        selections: fileKeyObj.MEDIA_TYPE + '= ?',
-        selectionArgs: [imageType.toString()],
-    }
-    let AlbumNoArgsFetchOp = {
-        selections: fileKeyObj.ALBUM_NAME + '= ?',
-        selectionArgs:['New Album 1']
-    }
-
-    let albumList = await media.getAlbums(AlbumNoArgsFetchOp);
-    if (albumList.length > 0) {
-        const album = albumList[0];
-        let fetchFileResult = await album.getFileAssets(imagesFetchOp);
-        let count = fetchFileResult.getCount();
-        console.info("get mediaLibrary IMAGE number", count);
-    } else {
-        console.info('getAlbum list is: 0');
-    }
+  const context = getContext(this);
+  let media = mediaLibrary.getMediaLibrary(context);
+  let fileKeyObj = mediaLibrary.FileKey;
+  let videoType = mediaLibrary.MediaType.VIDEO;
+  let videoFetchOp = {
+    selections: fileKeyObj.MEDIA_TYPE + '= ?',
+    selectionArgs: [videoType.toString()],
+  }
+  let AlbumNoArgsFetchOp = {
+    selections: fileKeyObj.ALBUM_NAME + '= ?',
+    selectionArgs:['New Album 1']
+  }
+
+  let albumList = await media.getAlbums(AlbumNoArgsFetchOp);
+  if (albumList.length > 0) {
+    const album = albumList[0];
+    let fetchFileResult = await album.getFileAssets(videoFetchOp);
+    let count = fetchFileResult.getCount();
+    console.info("get mediaLibrary VIDEO number", count);
+  } else {
+    console.info('getAlbum list is: 0');
+  }
 }
 ```
 
@@ -235,31 +242,32 @@ The following describes how to obtain the thumbnail (size: 720 x 720) of the fir
 
 ```ts
 async function getFirstThumbnailPromise() {
-    const context = getContext(this);
-    let media = mediaLibrary.getMediaLibrary(context);
-    let fileKeyObj = mediaLibrary.FileKey;
-    let imageType = mediaLibrary.MediaType.IMAGE;
-    let imagesFetchOp = {
-        selections: fileKeyObj.MEDIA_TYPE + '= ?',
-        selectionArgs: [imageType.toString()],
-    }
-
-    let size = { width: 720, height: 720 };
-    const fetchFileResult = await media.getFileAssets(imagesFetchOp);
-    if (fetchFileResult != undefined) {
-        const asset = await fetchFileResult.getFirstObject();
-        asset.getThumbnail(size).then((pixelMap) => {
-          pixelMap.getImageInfo().then((info) => {
-              console.info('get Thumbnail info: ' + "width: " + info.size.width + " height: " + info.size.height);
-          }).catch((err) => {
-              console.info("getImageInfo failed with error:" + err);
-          });
-        }).catch((err) => {
-            console.info("getImageInfo failed with error:" + err);
-        });
-    } else {
-        console.info("get image failed with error");
-    }
+  const context = getContext(this);
+  let media = mediaLibrary.getMediaLibrary(context);
+  let fileKeyObj = mediaLibrary.FileKey;
+  let imageType = mediaLibrary.MediaType.IMAGE;
+  let imagesFetchOp = {
+    selections: fileKeyObj.MEDIA_TYPE + '= ?',
+    selectionArgs: [imageType.toString()],
+  }
+
+  let size = { width: 720, height: 720 };
+  const fetchFileResult = await media.getFileAssets(imagesFetchOp);
+  if (fetchFileResult === undefined) {
+    console.error("get image failed with error");
+    return;
+  } else {
+    const asset = await fetchFileResult.getFirstObject();
+    asset.getThumbnail(size).then((pixelMap) => {
+      pixelMap.getImageInfo().then((info) => {
+        console.info('get Thumbnail info: ' + "width: " + info.size.width + " height: " + info.size.height);
+      }).catch((err) => {
+        console.error("getImageInfo failed with error: " + err);
+      });
+    }).catch((err) => {
+      console.error("getImageInfo failed with error: " + err);
+    });
+  }
 }
 ```
 
@@ -277,16 +285,16 @@ The following describes how to create a file of the **MediaType.FILE** type.
 
 ```ts
 async function example() {
-    let mediaType = mediaLibrary.MediaType.FILE;
-    let DIR_DOCUMENTS = mediaLibrary.DirectoryType.DIR_DOCUMENTS;
-    const context = getContext(this);
-    let media = mediaLibrary.getMediaLibrary(context);
-    const path = await media.getPublicDirectory(DIR_DOCUMENTS);
-    media.createAsset(mediaType, "testFile.text", path).then ((asset) => {
-        console.info("createAsset successfully:"+ JSON.stringify(asset));
-    }).catch((err) => {
-        console.info("createAsset failed with error:"+ err);
-    });
+  let mediaType = mediaLibrary.MediaType.FILE;
+  let DIR_DOCUMENTS = mediaLibrary.DirectoryType.DIR_DOCUMENTS;
+  const context = getContext(this);
+  let media = mediaLibrary.getMediaLibrary(context);
+  const path = await media.getPublicDirectory(DIR_DOCUMENTS);
+  media.createAsset(mediaType, "testFile.text", path).then((asset) => {
+    console.info("createAsset successfully:"+ JSON.stringify(asset));
+  }).catch((err) => {
+    console.error("createAsset failed with error: " + err);
+  });
 }
 ```
 
@@ -312,26 +320,26 @@ The following describes how to move the first file in the result set to the recy
 
 ```ts
 async function example() {
-    let fileKeyObj = mediaLibrary.FileKey;
-    let fileType = mediaLibrary.MediaType.FILE;
-    let option = {
-        selections: fileKeyObj.MEDIA_TYPE + '= ?',
-        selectionArgs: [fileType.toString()],
-    };
-    const context = getContext(this);
-    let media = mediaLibrary.getMediaLibrary(context);
-    const fetchFileResult = await media.getFileAssets(option);
-    let asset = await fetchFileResult.getFirstObject();
-    if (asset == undefined) {
-      console.error('asset not exist');
-      return;
-    }
-    // Void callback.
-    asset.trash(true).then(() => {
-        console.info("trash successfully");
-    }).catch((err) => {
-        console.info("trash failed with error: " + err);
-    });
+  let fileKeyObj = mediaLibrary.FileKey;
+  let fileType = mediaLibrary.MediaType.FILE;
+  let option = {
+    selections: fileKeyObj.MEDIA_TYPE + '= ?',
+    selectionArgs: [fileType.toString()],
+  };
+  const context = getContext(this);
+  let media = mediaLibrary.getMediaLibrary(context);
+  const fetchFileResult = await media.getFileAssets(option);
+  let asset = await fetchFileResult.getFirstObject();
+  if (asset === undefined) {
+    console.error('asset not exist');
+    return;
+  }
+  // Void callback.
+  asset.trash(true).then(() => {
+    console.info("trash successfully");
+  }).catch((err) => {
+    console.error("trash failed with error: " + err);
+  });
 }
 ```
 
@@ -346,7 +354,7 @@ Before renaming a file, you must obtain the file, for example, by calling [Fetch
 - You have obtained a **MediaLibrary** instance.
 - You have granted the permission **ohos.permission.WRITE_MEDIA**.
 
-The following describes how to rename the first file in the result set as **newtitle.text**.
+The following describes how to rename the first file in the result set as **newImage.jpg**.
 
 **How to Develop**
 
@@ -358,28 +366,28 @@ The following describes how to rename the first file in the result set as **newt
 
 ```ts
 async function example() {
-    let fileKeyObj = mediaLibrary.FileKey;
-    let fileType = mediaLibrary.MediaType.FILE;
-    let option = {
-        selections: fileKeyObj.MEDIA_TYPE + '= ?',
-        selectionArgs: [fileType.toString()],
-    };
-    const context = getContext(this);
-    let media = mediaLibrary.getMediaLibrary(context);
-    const fetchFileResult = await media.getFileAssets(option);
-    let asset = await fetchFileResult.getFirstObject();
-    if (asset == undefined) {
-      console.error('asset not exist');
+  let fileKeyObj = mediaLibrary.FileKey;
+  let fileType = mediaLibrary.MediaType.IMAGE;
+  let option = {
+    selections: fileKeyObj.MEDIA_TYPE + '= ?',
+    selectionArgs: [fileType.toString()],
+  };
+  const context = getContext(this);
+  let media = mediaLibrary.getMediaLibrary(context);
+  const fetchFileResult = await media.getFileAssets(option);
+  let asset = await fetchFileResult.getFirstObject();
+  if (asset === undefined) {
+    console.error('asset not exist');
+    return;
+  }
+  asset.displayName = 'newImage.jpg';
+  // Void callback.
+  asset.commitModify((err) => {
+    if (err) {
+      console.error('fileRename Failed ');
       return;
     }
-    asset.displayName = 'newImage.jpg';
-    // Void callback.
-    asset.commitModify((err) => {
-       if (err) {
-           console.error('fileRename Failed ');
-           return;
-       }
-       console.log('fileRename successful.');
-    });
+    console.info('fileRename successful.');
+  });
 }
 ```