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提交 3957a7fb 编写于 作者: P PaDaBoo
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Update data-Preferences file 

Signed-off-by: NPaDaBoo <xuejianwu@huawei.com>
上级 b4e18ea1
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Showing with 216 addition and 411 deletion
zh-cn/application-dev/reference/apis/js-apis-data-preferences.md
浏览文件 @ 3957a7fb
...@@ -35,38 +35,20 @@ getPreferences(context: Context, name: string, callback: AsyncCallback&lt;Prefer ...@@ -35,38 +35,20 @@ getPreferences(context: Context, name: string, callback: AsyncCallback&lt;Prefer
**参数：** **参数：**
| 参数名 | 类型 | 必填 | 说明 | | 参数名 | 类型 | 必填 | 说明 |
| -------- | -------- | -------- | -------- | | -------- | -------- | -------- | -------- |
| context | [Context](js-apis-Context.md) | 是 | 应用程序或功能的上下文。 | | context | [Context](js-apis-ability-context.md) | 是 | 应用程序或功能的上下文。 |
| name | string | 是 | 应用程序内部数据存储名称。 | | name | string | 是 | 应用程序内部数据存储名称。 |
| callback | AsyncCallback&lt;[Preferences](#preferences)&gt; | 是 | 回调函数。 | | callback | AsyncCallback&lt;[Preferences](#preferences)&gt; | 是 | 回调函数。 |
**示例：** **示例：**
```ts ```ts
import Ability from '@ohos.application.Ability' data_preferences.getPreferences(this.context, 'mystore', function (err, preferences) {
import data_preferences from '@ohos.data.preferences'
export default class MainAbility extends Ability {
data_preferences.getPreferences(this.context, 'mystore', function (err, preferences) {
if (err) { if (err) {
console.info("Get the preferences failed") console.info("Get preferences failed.")
return; return;
} }
preferences.put('startup', 'auto', function (err) { console.info("Get preferences successfully.")
if (err) { })
console.info("Put the value of startup failed, err: " + err) ```
return
}
console.info("Put the value of startup successfully.")
preferences.flush(function (err) {
if (err) {
console.info("Flush to file failed, err: " + err)
return
}
console.info("Flushed to file successfully.")
})
})
})
}
```
## data_preferences.getPreferences ## data_preferences.getPreferences
...@@ -80,7 +62,7 @@ getPreferences(context: Context, name: string): Promise&lt;Preferences&gt; ...@@ -80,7 +62,7 @@ getPreferences(context: Context, name: string): Promise&lt;Preferences&gt;
**参数：** **参数：**
| 参数名 | 类型 | 必填 | 说明 | | 参数名 | 类型 | 必填 | 说明 |
| -------- | -------- | -------- | -------- | | -------- | -------- | -------- | -------- |
| context | [Context](js-apis-Context.md) | 是 | 应用程序或功能的上下文。 | | context | [Context](js-apis-ability-context.md) | 是 | 应用程序或功能的上下文。 |
| name | string | 是 | 应用程序内部数据存储名称。 | | name | string | 是 | 应用程序内部数据存储名称。 |
**返回值：** **返回值：**
...@@ -89,32 +71,14 @@ getPreferences(context: Context, name: string): Promise&lt;Preferences&gt; ...@@ -89,32 +71,14 @@ getPreferences(context: Context, name: string): Promise&lt;Preferences&gt;
| Promise&lt;[Preferences](#preferences)&gt; | Promise实例，用于异步获取结果。 | | Promise&lt;[Preferences](#preferences)&gt; | Promise实例，用于异步获取结果。 |
**示例：** **示例：**
```ts ```ts
import Ability from '@ohos.application.Ability' let promise = data_preferences.getPreferences(this.context, 'mystore')
import data_preferences from '@ohos.data.preferences' promise.then((preferences) => {
export default class MainAbility extends Ability { console.info("Get preferences successfully.")
}).catch((err) => {
let promise = data_preferences.getPreferences(this.context, 'mystore') console.info("Get preferences failed.")
promise.then((preferences) => { })
preferences.put('startup', 'auto', function (err) { ```
if (err) {
console.info("Put the value of startup failed, err: " + err)
return
}
console.info("Put the value of startup successfully.")
preferences.flush(function (err) {
if (err) {
console.info("Flush to file failed, err: " + err)
return
}
console.info("Flushed to file successfully.")
})
})
}).catch((err) => {
console.info("Get the preferences failed")
})
}
```
## data_preferences.deletePreferences ## data_preferences.deletePreferences
...@@ -129,25 +93,20 @@ deletePreferences(context: Context, name: string, callback: AsyncCallback&lt;voi ...@@ -129,25 +93,20 @@ deletePreferences(context: Context, name: string, callback: AsyncCallback&lt;voi
**参数：** **参数：**
| 参数名 | 类型 | 必填 | 说明 | | 参数名 | 类型 | 必填 | 说明 |
| -------- | -------- | -------- | -------- | | -------- | -------- | -------- | -------- |
| context | [Context](js-apis-Context.md) | 是 | 应用程序或功能的上下文。 | | context | [Context](js-apis-ability-context.md) | 是 | 应用程序或功能的上下文。 |
| name | string | 是 | 应用程序内部数据存储名称。 | | name | string | 是 | 应用程序内部数据存储名称。 |
| callback | AsyncCallback&lt;void&gt; | 是 | 回调函数。 | | callback | AsyncCallback&lt;void&gt; | 是 | 回调函数。 |
**示例：** **示例：**
```ts ```ts
import Ability from '@ohos.application.Ability' data_preferences.deletePreferences(this.context, 'mystore', function (err) {
import data_preferences from '@ohos.data.preferences'
export default class MainAbility extends Ability {
data_preferences.deletePreferences(this.context, 'mystore', function (err) {
if (err) { if (err) {
console.info("Deleted failed, err: " + err) console.info("Deleted preferences failed, err: " + err)
return return
} }
console.info("Deleted successfully.") console.info("Deleted preferences successfully.")
}) })
} ```
```
## data_preferences.deletePreferences ## data_preferences.deletePreferences
...@@ -162,7 +121,7 @@ deletePreferences(context: Context, name: string): Promise&lt;void&gt; ...@@ -162,7 +121,7 @@ deletePreferences(context: Context, name: string): Promise&lt;void&gt;
**参数：** **参数：**
| 参数名 | 类型 | 必填 | 说明 | | 参数名 | 类型 | 必填 | 说明 |
| -------- | -------- | -------- | -------- | | -------- | -------- | -------- | -------- |
| context | [Context](js-apis-Context.md) | 是 | 应用程序或功能的上下文。 | | context | [Context](js-apis-ability-context.md) | 是 | 应用程序或功能的上下文。 |
| name | string | 是 | 应用程序内部数据存储名称。 | | name | string | 是 | 应用程序内部数据存储名称。 |
**返回值：** **返回值：**
...@@ -171,19 +130,14 @@ deletePreferences(context: Context, name: string): Promise&lt;void&gt; ...@@ -171,19 +130,14 @@ deletePreferences(context: Context, name: string): Promise&lt;void&gt;
| Promise&lt;void&gt; | Promise实例，用于异步获取结果。 | | Promise&lt;void&gt; | Promise实例，用于异步获取结果。 |
**示例：** **示例：**
```ts ```ts
import Ability from '@ohos.application.Ability' let promise = data_preferences.deletePreferences(this.context, 'mystore')
import data_preferences from '@ohos.data.preferences' promise.then(() => {
export default class MainAbility extends Ability { console.info("Deleted preferences successfully.")
}).catch((err) => {
let promise = data_preferences.deletePreferences(this.context, 'mystore') console.info("Deleted preferences failed, err: " + err)
promise.then(() => { })
console.info("Deleted successfully.") ```
}).catch((err) => {
console.info("Deleted failed, err: " + err)
})
}
```
## data_preferences.removePreferencesFromCache ## data_preferences.removePreferencesFromCache
...@@ -199,25 +153,20 @@ removePreferencesFromCache(context: Context, name: string, callback: AsyncCallba ...@@ -199,25 +153,20 @@ removePreferencesFromCache(context: Context, name: string, callback: AsyncCallba
**参数：** **参数：**
| 参数名 | 类型 | 必填 | 说明 | | 参数名 | 类型 | 必填 | 说明 |
| -------- | -------- | -------- | -------- | | -------- | -------- | -------- | -------- |
| context | [Context](js-apis-Context.md) | 是 | 应用程序或功能的上下文。 | | context | [Context](js-apis-ability-context.md) | 是 | 应用程序或功能的上下文。 |
| name | string | 是 | 应用程序内部数据存储名称。 | | name | string | 是 | 应用程序内部数据存储名称。 |
| callback | AsyncCallback&lt;void&gt; | 是 | 回调函数。 | | callback | AsyncCallback&lt;void&gt; | 是 | 回调函数。 |
**示例：** **示例：**
```ts ```ts
import Ability from '@ohos.application.Ability' data_preferences.removePreferencesFromCache(this.context, 'mystore', function (err) {
import data_preferences from '@ohos.data.preferences'
export default class MainAbility extends Ability {
data_preferences.removePreferencesFromCache(this.context, 'mystore', function (err) {
if (err) { if (err) {
console.info("Removed preferences from cache failed, err: " + err) console.info("Removed preferences from cache failed, err: " + err)
return return
} }
console.info("Removed preferences from cache successfully.") console.info("Removed preferences from cache successfully.")
}) })
} ```
```
## data_preferences.removePreferencesFromCache ## data_preferences.removePreferencesFromCache
...@@ -233,7 +182,7 @@ removePreferencesFromCache(context: Context, name: string): Promise&lt;void&gt; ...@@ -233,7 +182,7 @@ removePreferencesFromCache(context: Context, name: string): Promise&lt;void&gt;
**参数：** **参数：**
| 参数名 | 类型 | 必填 | 说明 | | 参数名 | 类型 | 必填 | 说明 |
| -------- | -------- | -------- | -------- | | -------- | -------- | -------- | -------- |
| context | [Context](js-apis-Context.md) | 是 | 应用程序或功能的上下文。 | | context | [Context](js-apis-ability-context.md) | 是 | 应用程序或功能的上下文。 |
| name | string | 是 | 应用程序内部数据存储名称。 | | name | string | 是 | 应用程序内部数据存储名称。 |
**返回值：** **返回值：**
...@@ -242,19 +191,14 @@ removePreferencesFromCache(context: Context, name: string): Promise&lt;void&gt; ...@@ -242,19 +191,14 @@ removePreferencesFromCache(context: Context, name: string): Promise&lt;void&gt;
| Promise&lt;void&gt; | Promise实例，用于异步获取结果。 | | Promise&lt;void&gt; | Promise实例，用于异步获取结果。 |
**示例：** **示例：**
```ts ```ts
import Ability from '@ohos.application.Ability' let promise = data_preferences.removePreferencesFromCache(this.context, 'mystore')
import data_preferences from '@ohos.data.preferences' promise.then(() => {
export default class MainAbility extends Ability {
let promise = data_preferences.removePreferencesFromCache(this.context, 'mystore')
promise.then(() => {
console.info("Removed preferences from cache successfully.") console.info("Removed preferences from cache successfully.")
}).catch((err) => { }).catch((err) => {
console.info("Removed preferences from cache failed, err: " + err) console.info("Removed preferences from cache failed, err: " + err)
}) })
} ```
```
## Preferences ## Preferences
...@@ -278,26 +222,15 @@ get(key: string, defValue: ValueType, callback: AsyncCallback&lt;ValueType&gt;): ...@@ -278,26 +222,15 @@ get(key: string, defValue: ValueType, callback: AsyncCallback&lt;ValueType&gt;):
| callback | AsyncCallback&lt;ValueType&gt; | 是 | 回调函数。 | | callback | AsyncCallback&lt;ValueType&gt; | 是 | 回调函数。 |
**示例：** **示例：**
```ts ```ts
import Ability from '@ohos.application.Ability'
import data_preferences from '@ohos.data.preferences'
export default class MainAbility extends Ability {
data_preferences.getPreferences(this.context, 'mystore', function (err, preferences) {
if (err) {
console.info("Get the preferences failed, err: " + err)
return
}
preferences.get('startup', 'default', function(err, value) { preferences.get('startup', 'default', function(err, value) {
if (err) { if (err) {
console.info("Get the value of startup failed, err: " + err) console.info("Get value of startup failed, err: " + err)
return return
} }
console.info("The value of startup is " + value) console.info("Get value of startup is " + value)
}) })
}) ```
}
```
### get ### get
...@@ -320,24 +253,14 @@ get(key: string, defValue: ValueType): Promise&lt;ValueType&gt; ...@@ -320,24 +253,14 @@ get(key: string, defValue: ValueType): Promise&lt;ValueType&gt;
| Promise&lt;ValueType&gt; | Promise实例，用于异步获取结果。 | | Promise&lt;ValueType&gt; | Promise实例，用于异步获取结果。 |
**示例：** **示例：**
```ts ```ts
import Ability from '@ohos.application.Ability' let promise = preferences.get('startup', 'default')
import data_preferences from '@ohos.data.preferences' promise.then((value) => {
export default class MainAbility extends Ability { console.info("Get value of startup is " + value)
}).catch((err) => {
let promise = data_preferences.getPreferences(this.context, 'mystore') console.info("Get value of startup failed, err: " + err)
promise.then((preferences) => { })
let promiseGet = preferences.get('startup', 'default') ```
promiseGet.then((value) => {
console.info("The value of startup is " + value)
}).catch((err) => {
console.info("Get the value of startup failed, err: " + err)
})
}).catch((err) => {
console.info("Get the preferences failed, err: " + err)
})
}
```
### put ### put
...@@ -356,26 +279,15 @@ put(key: string, value: ValueType, callback: AsyncCallback&lt;void&gt;): void ...@@ -356,26 +279,15 @@ put(key: string, value: ValueType, callback: AsyncCallback&lt;void&gt;): void
| callback | AsyncCallback&lt;void&gt; | 是 | 回调函数。 | | callback | AsyncCallback&lt;void&gt; | 是 | 回调函数。 |
**示例：** **示例：**
```ts ```ts
import Ability from '@ohos.application.Ability' preferences.put('startup', 'auto', function (err) {
import data_preferences from '@ohos.data.preferences'
export default class MainAbility extends Ability {
data_preferences.getPreferences(this.context, 'mystore', function (err, preferences) {
if (err) {
console.info("Get the preferences failed, err: " + err)
return
}
preferences.put('startup', 'auto', function (err) {
if (err) { if (err) {
console.info("Put the value of startup failed, err: " + err) console.info("Put value of startup failed, err: " + err)
return return
} }
console.info("Put the value of startup successfully.") console.info("Put value of startup successfully.")
}) })
}) ```
}
```
### put ### put
...@@ -398,24 +310,14 @@ put(key: string, value: ValueType): Promise&lt;void&gt; ...@@ -398,24 +310,14 @@ put(key: string, value: ValueType): Promise&lt;void&gt;
| Promise&lt;void&gt; | Promise实例，用于异步处理。 | | Promise&lt;void&gt; | Promise实例，用于异步处理。 |
**示例：** **示例：**
```ts ```ts
import Ability from '@ohos.application.Ability' let promise = preferences.put('startup', 'auto')
import data_preferences from '@ohos.data.preferences' promise.then(() => {
export default class MainAbility extends Ability { console.info("Put value of startup successfully.")
}).catch((err) => {
let promise = data_preferences.getPreferences(this.context, 'mystore') console.info("Put value of startup failed, err: " + err)
promise.then((preferences) => { })
let promisePut = preferences.put('startup', 'auto') ```
promisePut.then(() => {
console.info("Put the value of startup successfully.")
}).catch((err) => {
console.info("Put the value of startup failed, err: " + err)
})
}).catch((err) => {
console.info("Get the preferences failed, err: " + err)
})
}
```
### has ### has
...@@ -438,17 +340,8 @@ has(key: string, callback: AsyncCallback&lt;boolean&gt;): boolean ...@@ -438,17 +340,8 @@ has(key: string, callback: AsyncCallback&lt;boolean&gt;): boolean
| boolean | true表示存在，false表示不存在。 | | boolean | true表示存在，false表示不存在。 |
**示例：** **示例：**
```ts ```ts
import Ability from '@ohos.application.Ability' preferences.has('startup', function (err, isExist) {
import data_preferences from '@ohos.data.preferences'
export default class MainAbility extends Ability {
data_preferences.getPreferences(this.context, 'mystore', function (err, preferences) {
if (err) {
console.info("Get the preferences failed, err: " + err)
return
}
preferences.has('startup', function (err, isExist) {
if (err) { if (err) {
console.info("Check the key of startup failed, err: " + err) console.info("Check the key of startup failed, err: " + err)
return return
...@@ -458,10 +351,8 @@ has(key: string, callback: AsyncCallback&lt;boolean&gt;): boolean ...@@ -458,10 +351,8 @@ has(key: string, callback: AsyncCallback&lt;boolean&gt;): boolean
} else { } else {
console.info("The key of startup dose not contain.") console.info("The key of startup dose not contain.")
} }
}) })
}) ```
}
```
### has ### has
...@@ -483,28 +374,18 @@ has(key: string): Promise&lt;boolean&gt; ...@@ -483,28 +374,18 @@ has(key: string): Promise&lt;boolean&gt;
| Promise&lt;boolean&gt; | Promise实例，用于异步处理。 | | Promise&lt;boolean&gt; | Promise实例，用于异步处理。 |
**示例：** **示例：**
```ts ```ts
import Ability from '@ohos.application.Ability' let promise = preferences.has('startup')
import data_preferences from '@ohos.data.preferences' promise.then((isExist) => {
export default class MainAbility extends Ability {
let promise = data_preferences.getPreferences(this.context, 'mystore')
promise.then((preferences) => {
let promiseHas = preferences.has('startup')
promiseHas.then((isExist) => {
if (isExist) { if (isExist) {
console.info("The key of startup is contained.") console.info("The key of startup is contained.")
} else { } else {
console.info("The key of startup dose not contain.") console.info("The key of startup dose not contain.")
} }
}).catch((err) => { }).catch((err) => {
console.info("Check the key of startup failed, err: " + err) console.info("Check the key of startup failed, err: " + err)
}) })
}).catch((err) => { ```
console.info("Get the preferences failed, err: " + err)
})
}
```
### delete ### delete
...@@ -522,26 +403,15 @@ delete(key: string, callback: AsyncCallback&lt;void&gt;): void ...@@ -522,26 +403,15 @@ delete(key: string, callback: AsyncCallback&lt;void&gt;): void
| callback | AsyncCallback&lt;void&gt; | 是 | 回调函数。 | | callback | AsyncCallback&lt;void&gt; | 是 | 回调函数。 |
**示例：** **示例：**
```ts ```ts
import Ability from '@ohos.application.Ability' preferences.delete('startup', function (err) {
import data_preferences from '@ohos.data.preferences'
export default class MainAbility extends Ability {
data_preferences.getPreferences(this.context, 'mystore', function (err, preferences) {
if (err) {
console.info("Get the preferences failed, err: " + err)
return
}
preferences.delete('startup', function (err) {
if (err) { if (err) {
console.info("Delete startup key failed, err: " + err) console.info("Delete startup key failed, err: " + err)
return return
} }
console.info("Deleted startup key successfully.") console.info("Deleted startup key successfully.")
}) })
}) ```
}
```
### delete ### delete
...@@ -563,24 +433,14 @@ delete(key: string): Promise&lt;void&gt; ...@@ -563,24 +433,14 @@ delete(key: string): Promise&lt;void&gt;
| Promise&lt;void&gt; | Promise实例，用于异步处理。 | | Promise&lt;void&gt; | Promise实例，用于异步处理。 |
**示例：** **示例：**
```ts ```ts
import Ability from '@ohos.application.Ability' let promise = preferences.delete('startup')
import data_preferences from '@ohos.data.preferences' promise.then(() => {
export default class MainAbility extends Ability {
let promise = data_preferences.getPreferences(this.context, 'mystore')
promise.then((preferences) => {
let promiseDelete = preferences.delete('startup')
promiseDelete.then(() => {
console.info("Deleted startup key successfully.") console.info("Deleted startup key successfully.")
}).catch((err) => { }).catch((err) => {
console.info("Delete startup key failed, err: " + err) console.info("Delete startup key failed, err: " + err)
}) })
}).catch((err) => { ```
console.info("Get the preferences failed, err: " + err)
})
}
```
### flush ### flush
...@@ -597,26 +457,15 @@ flush(callback: AsyncCallback&lt;void&gt;): void ...@@ -597,26 +457,15 @@ flush(callback: AsyncCallback&lt;void&gt;): void
| callback | AsyncCallback&lt;void&gt; | 是 | 回调函数。 | | callback | AsyncCallback&lt;void&gt; | 是 | 回调函数。 |
**示例：** **示例：**
```ts ```ts
import Ability from '@ohos.application.Ability' preferences.flush(function (err) {
import data_preferences from '@ohos.data.preferences'
export default class MainAbility extends Ability {
data_preferences.getPreferences(this.context, 'mystore', function (err, preferences) {
if (err) {
console.info("Get the preferences failed, err: " + err)
return
}
preferences.flush(function (err) {
if (err) { if (err) {
console.info("Flush to file failed, err: " + err) console.info("Flush to file failed, err: " + err)
return return
} }
console.info("Flushed to file successfully.") console.info("Flushed to file successfully.")
}) })
}) ```
}
```
### flush ### flush
...@@ -633,24 +482,14 @@ flush(): Promise&lt;void&gt; ...@@ -633,24 +482,14 @@ flush(): Promise&lt;void&gt;
| Promise&lt;void&gt; | Promise实例，用于异步处理。 | | Promise&lt;void&gt; | Promise实例，用于异步处理。 |
**示例：** **示例：**
```ts ```ts
import Ability from '@ohos.application.Ability' let promise = preferences.flush()
import data_preferences from '@ohos.data.preferences' promise.then(() => {
export default class MainAbility extends Ability {
let promise = data_preferences.getPreferences(this.context, 'mystore')
promise.then((preferences) => {
let promiseFlush = preferences.flush()
promiseFlush.then(() => {
console.info("Flushed to file successfully.") console.info("Flushed to file successfully.")
}).catch((err) => { }).catch((err) => {
console.info("Flush to file failed, err: " + err) console.info("Flush to file failed, err: " + err)
}) })
}).catch((err) => { ```
console.info("Get the preferences failed, err: " + err)
})
}
```
### clear ### clear
...@@ -667,26 +506,15 @@ clear(callback: AsyncCallback&lt;void&gt;): void ...@@ -667,26 +506,15 @@ clear(callback: AsyncCallback&lt;void&gt;): void
| callback | AsyncCallback&lt;void&gt; | 是 | 回调函数。 | | callback | AsyncCallback&lt;void&gt; | 是 | 回调函数。 |
**示例：** **示例：**
```ts ```ts
import Ability from '@ohos.application.Ability' preferences.clear(function (err) {
import data_preferences from '@ohos.data.preferences'
export default class MainAbility extends Ability {
data_preferences.getPreferences(this.context, 'mystore', function (err, preferences) {
if (err) {
console.info("Get the preferences failed, err: " + err)
return
}
preferences.clear(function (err) {
if (err) { if (err) {
console.info("Clear to file failed, err: " + err) console.info("Clear to file failed, err: " + err)
return return
} }
console.info("Cleared to file successfully.") console.info("Cleared to file successfully.")
}) })
}) ```
}
```
### clear ### clear
...@@ -703,24 +531,14 @@ clear(): Promise&lt;void&gt; ...@@ -703,24 +531,14 @@ clear(): Promise&lt;void&gt;
| Promise&lt;void&gt; | Promise实例，用于异步处理。 | | Promise&lt;void&gt; | Promise实例，用于异步处理。 |
**示例：** **示例：**
```ts ```ts
import Ability from '@ohos.application.Ability' let promise = preferences.clear()
import data_preferences from '@ohos.data.preferences' promise.then(() => {
export default class MainAbility extends Ability {
let promise = data_preferences.getPreferences(this.context, 'mystore')
promise.then((preferences) => {
let promiseClear = preferences.clear()
promiseClear.then(() => {
console.info("Cleared to file successfully.") console.info("Cleared to file successfully.")
}).catch((err) => { }).catch((err) => {
console.info("Clear to file failed, err: " + err) console.info("Clear to file failed, err: " + err)
}) })
}).catch((err) => { ```
console.info("Get the preferences failed, err: " + err)
})
}
```
### on('change') ### on('change')
...@@ -738,26 +556,21 @@ on(type: 'change', callback: Callback&lt;{ key : string }&gt;): void ...@@ -738,26 +556,21 @@ on(type: 'change', callback: Callback&lt;{ key : string }&gt;): void
| callback | Callback&lt;{ key : string }&gt; | 回调对象实例。 | | callback | Callback&lt;{ key : string }&gt; | 回调对象实例。 |
**示例：** **示例：**
```ts ```ts
import Ability from '@ohos.application.Ability' var observer = function (key) {
import data_preferences from '@ohos.data.preferences'
export default class MainAbility extends Ability {
var observer = function (key) {
console.info("The key of " + key + " changed.") console.info("The key of " + key + " changed.")
} }
data_preferences.getPreferences(this.context, 'mystore', function (err, preferences) {
if (err) { ...
console.info("Get the preferences failed, err: " + err)
return preferences.on('change', observer)
} preferences.put('startup', 'auto', function (err) {
preferences.on('change', observer)
preferences.put('startup', 'auto', function (err) {
if (err) { if (err) {
console.info("Put the value of startup failed, err: " + err) console.info("Put the value of startup failed, err: " + err)
return return
} }
console.info("Put the value of startup successfully.") console.info("Put the value of startup successfully.")
preferences.flush(function (err) { preferences.flush(function (err) {
if (err) { if (err) {
console.info("Flush to file failed, err: " + err) console.info("Flush to file failed, err: " + err)
...@@ -765,10 +578,8 @@ on(type: 'change', callback: Callback&lt;{ key : string }&gt;): void ...@@ -765,10 +578,8 @@ on(type: 'change', callback: Callback&lt;{ key : string }&gt;): void
} }
console.info("Flushed to file successfully.") // observer will be called. console.info("Flushed to file successfully.") // observer will be called.
}) })
}) })
}) ```
}
```
### off('change') ### off('change')
...@@ -786,25 +597,21 @@ off(type: 'change', callback: Callback&lt;{ key : string }&gt;): void ...@@ -786,25 +597,21 @@ off(type: 'change', callback: Callback&lt;{ key : string }&gt;): void
| callback | Callback&lt;{ key : string }&gt; | 需要取消的回调对象实例。 | | callback | Callback&lt;{ key : string }&gt; | 需要取消的回调对象实例。 |
**示例：** **示例：**
```ts ```ts
import Ability from '@ohos.application.Ability' var observer = function (key) {
import data_preferences from '@ohos.data.preferences'
export default class MainAbility extends Ability {
var observer = function (key) {
console.info("The key of " + key + " changed.") console.info("The key of " + key + " changed.")
} }
data_preferences.getPreferences(this.context, 'mystore', function (err, preferences) {
if (err) { ...
console.info("Get the preferences failed, err: " + err)
return preferences.on('change', observer)
} preferences.put('startup', 'auto', function (err) {
preferences.on('change', observer)
preferences.put('startup', 'auto', function (err) {
if (err) { if (err) {
console.info("Put the value of startup failed, err: " + err) console.info("Put the value of startup failed, err: " + err)
return return
} }
console.info("Put the value of startup successfully.") console.info("Put the value of startup successfully.")
preferences.flush(function (err) { preferences.flush(function (err) {
if (err) { if (err) {
console.info("Flush to file failed, err: " + err) console.info("Flush to file failed, err: " + err)
...@@ -813,10 +620,8 @@ off(type: 'change', callback: Callback&lt;{ key : string }&gt;): void ...@@ -813,10 +620,8 @@ off(type: 'change', callback: Callback&lt;{ key : string }&gt;): void
console.info("Flushed to file successfully.") // observer will be called. console.info("Flushed to file successfully.") // observer will be called.
preferences.off('change', observer) preferences.off('change', observer)
}) })
}) })
}) ```
}
```
## ValueType ## ValueType
......
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