Skip to content

D
Docs

OpenHarmony / Docs
1 年多 前同步成功

通知 159
Star 292
Fork 28
D
Docs
未验证 提交 d44ed7c0 编写于 作者: O openharmony_ci 提交者： Gitee
浏览文件
操作

!9993 [翻译完成】#I5P4W5 

Merge pull request !9993 from Annie_wang/PR8973
上级 cc312e51 3fba769f
隐藏空白更改
内联 并排
Showing with 54 addition and 56 deletion
en/application-dev/reference/apis/js-apis-data-preferences.md
浏览文件 @ d44ed7c0
......@@ -39,8 +39,8 @@ Obtains a **Preferences** instance. This API uses an asynchronous callback to re
| Name | Type | Mandatory| Description |
| -------- | ------------------------------------------------ | ---- | ------------------------------------------------------------ |
| context | [Context](js-apis-ability-context.md) | Yes | Application context. |
| name | string | Yes | Name of the **Preferences** instance. |
| callback | AsyncCallback<[Preferences](#preferences)> | Yes | Callback invoked to return the result. If the operation is successful, **err** is **undefined** and **object** is the **Preferences** instance obtained. Otherwise, **err** is an error code.|
| name | string | Yes | Name of the **Preferences** instance. |
| callback | AsyncCallback<[Preferences](#preferences)> | Yes | Callback invoked to return the result. If the operation is successful, **err** is undefined and the **Preferences** instance obtained is returned. Otherwise, **err** is an error code.|
**Example**
......@@ -66,12 +66,14 @@ Obtains a **Preferences** instance. This API uses a promise to return the result
**System capability**: SystemCapability.DistributedDataManager.Preferences.Core
**Parameters**
| Name | Type | Mandatory| Description |
| ------- | ------------------------------------- | ---- | -------------------------- |
| context | [Context](js-apis-ability-context.md) | Yes | Application context. |
| Name | Type | Mandatory| Description |
| ------- | ------------------------------------- | ---- | ----------------------- |
| context | [Context](js-apis-ability-context.md) | Yes | Application context. |
| name | string | Yes | Name of the **Preferences** instance.|
**Return value**
| Type | Description |
| ------------------------------------------ | ---------------------------------- |
| Promise<[Preferences](#preferences)> | Promise used to return the **Preferences** instance obtained.|
......@@ -103,6 +105,7 @@ The deleted **Preferences** instance cannot be used for data operations. Otherwi
**System capability**: SystemCapability.DistributedDataManager.Preferences.Core
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ------------------------------------- | ---- | ---------------------------------------------------- |
| context | [Context](js-apis-ability-context.md) | Yes | Application context. |
......@@ -110,6 +113,7 @@ The deleted **Preferences** instance cannot be used for data operations. Otherwi
| callback | AsyncCallback<void> | Yes | Callback invoked to return the result. If the operation is successful, **err** is **undefined**. Otherwise, **err** is an error code.|
**Example**
```js
data_preferences.deletePreferences(this.context, 'mystore', function (err) {
if (err) {
......@@ -134,17 +138,20 @@ The deleted **Preferences** instance cannot be used for data operations. Otherwi
**System capability**: SystemCapability.DistributedDataManager.Preferences.Core
**Parameters**
| Name | Type | Mandatory| Description |
| ------- | ------------------------------------- | ---- | -------------------------- |
| context | [Context](js-apis-ability-context.md) | Yes | Application context. |
| Name | Type | Mandatory| Description |
| ------- | ------------------------------------- | ---- | ----------------------- |
| context | [Context](js-apis-ability-context.md) | Yes | Application context. |
| name | string | Yes | Name of the **Preferences** instance to delete.|
**Return value**
| Type | Description |
| ------------------- | ------------------------- |
| Promise<void> | Promise that returns no value.|
**Example**
```js
let promise = data_preferences.deletePreferences(this.context, 'mystore')
promise.then(() => {
......@@ -166,6 +173,7 @@ The removed **Preferences** instance cannot be used for data operations. Otherwi
**System capability**: SystemCapability.DistributedDataManager.Preferences.Core
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ------------------------------------- | ---- | ---------------------------------------------------- |
| context | [Context](js-apis-ability-context.md) | Yes | Application context. |
......@@ -173,6 +181,7 @@ The removed **Preferences** instance cannot be used for data operations. Otherwi
| callback | AsyncCallback<void> | Yes | Callback invoked to return the result. If the operation is successful, **err** is **undefined**. Otherwise, **err** is an error code.|
**Example**
```js
data_preferences.removePreferencesFromCache(this.context, 'mystore', function (err) {
if (err) {
......@@ -195,17 +204,20 @@ The removed **Preferences** instance cannot be used for data operations. Otherwi
**System capability**: SystemCapability.DistributedDataManager.Preferences.Core
**Parameters**
| Name | Type | Mandatory| Description |
| ------- | ------------------------------------- | ---- | -------------------------- |
| context | [Context](js-apis-ability-context.md) | Yes | Application context. |
| Name | Type | Mandatory| Description |
| ------- | ------------------------------------- | ---- | ----------------------- |
| context | [Context](js-apis-ability-context.md) | Yes | Application context. |
| name | string | Yes | Name of the **Preferences** instance to remove.|
**Return value**
| Type | Description |
| ------------------- | ------------------------- |
| Promise<void> | Promise that returns no value.|
**Example**
```js
let promise = data_preferences.removePreferencesFromCache(this.context, 'mystore')
promise.then(() => {
......@@ -232,6 +244,7 @@ Obtains the value of a key. This API uses an asynchronous callback to return the
**System capability**: SystemCapability.DistributedDataManager.Preferences.Core
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | -------------------------------------------- | ---- | ------------------------------------------------------------ |
| key | string | Yes | Key of the data to obtain. It cannot be empty. |
......@@ -260,6 +273,7 @@ Obtains the value of a key. This API uses a promise to return the result. If the
**System capability**: SystemCapability.DistributedDataManager.Preferences.Core
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ----------------------- | ---- | ------------------------------------------------------------ |
| key | string | Yes | Key of the data to obtain. It cannot be empty. |
......@@ -272,6 +286,7 @@ Obtains the value of a key. This API uses a promise to return the result. If the
| Promise<[ValueType](#valuetype)&gt; | Promise used to return the value obtained.|
**Example**
```js
let promise = preferences.get('startup', 'default');
promise.then((data) => {
......@@ -290,6 +305,7 @@ Obtains an **Object** instance that contains all KV pairs. This API uses an asyn
**System capability**: SystemCapability.DistributedDataManager.Preferences.Core
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | --------------------------- | ---- | ------------------------------------------------------------ |
| callback | AsyncCallback&lt;Object&gt; | Yes | Callback invoked to return the result. If the operation is successful, **err** is **undefined** and **value** is the **Object** instance obtained. Otherwise, **err** is an error code.|
......@@ -318,11 +334,13 @@ Obtains an **Object** instance that contains all KV pairs. This API uses a promi
**System capability**: SystemCapability.DistributedDataManager.Preferences.Core
**Return value**
| Type | Description |
| --------------------- | ------------------------------------------- |
| Promise&lt;Object&gt; | Promise used to return the **Object** instance obtained.|
**Example**
```js
let promise = preferences.getAll();
promise.then((value) => {
......@@ -343,6 +361,7 @@ Writes data to this **Preferences** instance. This API uses an asynchronous call
**System capability**: SystemCapability.DistributedDataManager.Preferences.Core
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ------------------------- | ---- | ------------------------------------------------------------ |
| key | string | Yes | Key of the data. It cannot be empty. |
......@@ -350,6 +369,7 @@ Writes data to this **Preferences** instance. This API uses an asynchronous call
| callback | AsyncCallback&lt;void&gt; | Yes | Callback invoked to return the result. If the operation is successful, **err** is undefined. Otherwise, **err** is an error code. |
**Example**
```js
preferences.put('startup', 'auto', function (err) {
if (err) {
......@@ -370,17 +390,20 @@ Writes data to this **Preferences** instance. This API uses a promise to return
**System capability**: SystemCapability.DistributedDataManager.Preferences.Core
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ----------------------- | ---- | ------------------------------------------------------------ |
| key | string | Yes | Key of the data. It cannot be empty. |
| value | [ValueType](#valuetype) | Yes | Value to write. The value can be a number, a string, a Boolean value, or an array of numbers, strings, or Boolean values.|
**Return value**
| Type | Description |
| ------------------- | ------------------------- |
| Promise&lt;void&gt; | Promise that returns no value.|
**Example**
```js
let promise = preferences.put('startup', 'auto');
promise.then(() => {
......@@ -400,12 +423,14 @@ Checks whether this **Preferences** instance contains a KV pair of the given key
**System capability**: SystemCapability.DistributedDataManager.Preferences.Core
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ---------------------------- | ---- | ------------------------------------------------------------ |
| key | string | Yes | Key of the data to check. It cannot be empty. |
| callback | AsyncCallback&lt;boolean&gt; | Yes | Callback invoked to return the result. If the **Preferences** instance contains the KV pair, **true** will be returned. Otherwise, **false** will be returned.|
**Example**
```js
preferences.has('startup', function (err, isExist) {
if (err) {
......@@ -430,11 +455,13 @@ Checks whether this **Preferences** instance contains data with the given key. T
**System capability**: SystemCapability.DistributedDataManager.Preferences.Core
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | ------------------------------- |
| key | string | Yes | Key of the data to check. It cannot be empty.|
**Return value**
| Type | Description |
| ---------------------- | ------------------------------------------------------------ |
| Promise&lt;boolean&gt; | Promise used to return the result. If the **Preferences** instance contains the KV pair, **true** will be returned. Otherwise, **false** will be returned.|
......@@ -464,12 +491,14 @@ Deletes a KV pair from this **Preferences** instance. This API uses an asynchron
**System capability**: SystemCapability.DistributedDataManager.Preferences.Core
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ------------------------- | ---- | ---------------------------------------------------- |
| key | string | Yes | Key of the KV pair to delete. It cannot be empty. |
| callback | AsyncCallback&lt;void&gt; | Yes | Callback invoked to return the result. If the operation is successful, **err** is **undefined**. Otherwise, **err** is an error code.|
**Example**
```js
preferences.delete('startup', function (err) {
if (err) {
......@@ -490,16 +519,19 @@ Deletes a KV pair from this **Preferences** instance. This API uses a promise to
**System capability**: SystemCapability.DistributedDataManager.Preferences.Core
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | ------------------------------- |
| key | string | Yes | Key of the KV pair to delete. It cannot be empty.|
**Return value**
| Type | Description |
| ------------------- | ------------------------- |
| Promise&lt;void&gt; | Promise that returns no value.|
**Example**
```js
let promise = preferences.delete('startup');
promise.then(() => {
......@@ -514,16 +546,18 @@ promise.then(() => {
flush(callback: AsyncCallback&lt;void&gt;): void
Saves the data of the **Preferences** instance to a file asynchronously. This API uses an asynchronous callback to return the result.
Asynchronously stores data of this **Preferences** instance to its persistent file. This API uses a asynchronous callback to return the result.
**System capability**: SystemCapability.DistributedDataManager.Preferences.Core
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ------------------------- | ---- | ---------------------------------------------------- |
| callback | AsyncCallback&lt;void&gt; | Yes | Callback invoked to return the result. If the operation is successful, **err** is **undefined**. Otherwise, **err** is an error code.|
**Example**
```js
preferences.flush(function (err) {
if (err) {
......@@ -539,16 +573,18 @@ preferences.flush(function (err) {
flush(): Promise&lt;void&gt;
Saves the data of the **Preferences** instance to a file asynchronously. This API uses a promise to return the result.
Asynchronously stores data of this **Preferences** instance to its persistent file. This API uses a promise to return the result.
**System capability**: SystemCapability.DistributedDataManager.Preferences.Core
**Return value**
| Type | Description |
| ------------------- | ------------------------- |
| Promise&lt;void&gt; | Promise that returns no value.|
**Example**
```js
let promise = preferences.flush();
promise.then(() => {
......@@ -568,11 +604,13 @@ Clears this **Preferences** instance. This API uses an asynchronous callback to
**System capability**: SystemCapability.DistributedDataManager.Preferences.Core
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ------------------------- | ---- | ---------------------------------------------------- |
| callback | AsyncCallback&lt;void&gt; | Yes | Callback invoked to return the result. If the operation is successful, **err** is **undefined**. Otherwise, **err** is an error code.|
**Example**
```js
preferences.clear(function (err) {
if (err) {
......@@ -593,11 +631,13 @@ Clears this **Preferences** instance. This API uses a promise to return the resu
**System capability**: SystemCapability.DistributedDataManager.Preferences.Core
**Return value**
| Type | Description |
| ------------------- | ------------------------- |
| Promise&lt;void&gt; | Promise that returns no value.|
**Example**
```js
let promise = preferences.clear()
promise.then(() => {
......@@ -617,56 +657,14 @@ Subscribes to data changes. A callback will be triggered to return the new value
**System capability**: SystemCapability.DistributedDataManager.Preferences.Core
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | -------------------------------- | ---- | ---------------------------------------- |
| type | string | Yes | Event type to subscribe to. The value **change** indicates data change events.|
| callback | Callback&lt;{ key : string }&gt; | Yes | Callback invoked to return data changes. |
**Example**
```js
data_preferences.getPreferences(this.context, 'mystore', function (err, preferences) {
if (err) {
console.info("Failed to get the preferences.");
return;
}
var observer = function (key) {
console.info("The key " + key + " changed.");
}
preferences.on('change', observer);
preferences.put('startup', 'auto', function (err) {
if (err) {
console.info("Failed to put the value of 'startup'. Cause: " + err);
return;
}
console.info("Put the value of 'startup' successfully.");
preferences.flush(function (err) {
if (err) {
console.info("Failed to flush data. Cause: " + err);
return;
}
console.info("Flushed data successfully."); // The observer will be called.
})
})
})
```
### off('change')
off(type: 'change', callback?: Callback&lt;{ key : string }&gt;): void
Unsubscribes from data changes.
**System capability**: SystemCapability.DistributedDataManager.Preferences.Core
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | -------------------------------- | ---- | ------------------------------------------ |
| type | string | Yes | Event type to unsubscribe from. The value **change** indicates data change events. |
| callback | Callback&lt;{ key : string }&gt; | No | Callback to unregister. If this parameter is left blank, the callbacks used to subscribing to all data changes will be unregistered.|
**Example**
```js
data_preferences.getPreferences(this.context, 'mystore', function (err, preferences) {
if (err) {
......
Markdown is supported
0% 或 .
You are about to add 0 people to the discussion. Proceed with caution.
先完成此消息的编辑！
想要评论请 注册 或