提交 dca5036f 编写于 作者: L li_juntao

修改preference相关示例代码及描述

Signed-off-by: Nli_juntao <lijuntao9@huawei.com>
上级 d93d9aee
...@@ -26,7 +26,7 @@ ...@@ -26,7 +26,7 @@
| 类名 | 接口名 | 描述 | | 类名 | 接口名 | 描述 |
| ------- | -------------------------------------------------- | ----------------------------------------------- | | ------- | -------------------------------------------------- | ----------------------------------------------- |
| Preferences | put(key: string, value: ValueType): Promise\<void> | 支持值为number、string、boolean类型的数据存入。 | | Preferences | put(key: string, value: ValueType): Promise\<void> | 支持值为number、string、boolean类型的数据存入,同时也支持Array<number>、Array<string>、Array<boolean>三种类型的数组的存入。 |
### 读取数据 ### 读取数据
...@@ -36,7 +36,7 @@ ...@@ -36,7 +36,7 @@
| 类名 | 接口名 | 描述 | | 类名 | 接口名 | 描述 |
| ------- | ---------------------------------------------------------- | ----------------------------------------------- | | ------- | ---------------------------------------------------------- | ----------------------------------------------- |
| Preferences | get(key: string, defValue: ValueType): Promise\<ValueType> | 支持获取值为number、string、boolean类型的数据。 | | Preferences | get(key: string, defValue: ValueType): Promise\<ValueType> | 支持获取值为number、string、boolean类型的数据,同时也支持获取值为Array<number>、Array<string>、Array<boolean>三种数组类型的数据。 |
### 数据持久化 ### 数据持久化
...@@ -75,14 +75,14 @@ ...@@ -75,14 +75,14 @@
1. 准备工作,导入@ohos.data.preferences以及相关的模块到开发环境。 1. 准备工作,导入@ohos.data.preferences以及相关的模块到开发环境。
```js ```js
import data_preferences from '@ohos.data.preferences' import preferences from '@ohos.data.preferences'
``` ```
2. 获取Preferences实例。 2. 获取Preferences实例。
读取指定文件,将数据加载到Preferences实例,用于数据操作。 读取指定文件,将数据加载到Preferences实例,用于数据操作。
```js ```js
let promise = data_preferences.getPreferences(this.context, 'mystore') let promise = preferences.getPreferences(this.context, 'mystore')
``` ```
3. 存入数据。 3. 存入数据。
...@@ -90,9 +90,9 @@ ...@@ -90,9 +90,9 @@
使用Preferences put方法保存数据到缓存的实例中。 使用Preferences put方法保存数据到缓存的实例中。
```js ```js
promise.then((preferences) => { promise.then((pref) => {
let getPromise = preferences.put('startup', 'auto') let putPromise = pref.put('startup', 'auto')
getPromise.then(() => { putPromise.then(() => {
console.info("Put the value of startup successfully.") console.info("Put the value of startup successfully.")
}).catch((err) => { }).catch((err) => {
console.info("Put the value of startup failed with err: " + err) console.info("Put the value of startup failed with err: " + err)
...@@ -107,8 +107,8 @@ ...@@ -107,8 +107,8 @@
使用Preferences get方法读取数据。 使用Preferences get方法读取数据。
```js ```js
promise.then((preferences) => { promise.then((pref) => {
let getPromise = preferences.get('startup', 'default') let getPromise = pref.get('startup', 'default')
getPromise.then((value) => { getPromise.then((value) => {
console.info("The value of startup is " + value) console.info("The value of startup is " + value)
}).catch((err) => { }).catch((err) => {
...@@ -123,7 +123,7 @@ ...@@ -123,7 +123,7 @@
应用存入数据到Preferences实例后,可以通过flush方法将Preferences实例回写到文件中。 应用存入数据到Preferences实例后,可以通过flush方法将Preferences实例回写到文件中。
```js ```js
preferences.flush(); pref.flush();
``` ```
6. 订阅数据变化。 6. 订阅数据变化。
...@@ -134,14 +134,14 @@ ...@@ -134,14 +134,14 @@
var observer = function (key) { var observer = function (key) {
console.info("The key of " + key + " changed.") console.info("The key of " + key + " changed.")
} }
preferences.on('change', observer) pref.on('change', observer)
preferences.put('startup', 'auto', function (err) { pref.put('startup', 'auto', function (err) {
if (err) { if (err) {
console.info("Put the value of startup failed with err: " + err) console.info("Put the value of startup failed with err: " + err)
return return
} }
console.info("Put the value of startup successfully.") console.info("Put the value of startup successfully.")
preferences.flush(function (err) { pref.flush(function (err) {
if (err) { if (err) {
console.info("Flush to file failed with err: " + err) console.info("Flush to file failed with err: " + err)
return return
...@@ -156,8 +156,8 @@ ...@@ -156,8 +156,8 @@
使用deletePreferences方法从内存中移除指定文件对应的Preferences单实例,并删除指定文件及其备份文件、损坏文件。删除指定文件时,应用不允许再使用该实例进行数据操作,否则会出现数据一致性问题。删除后,数据及文件将不可恢复。 使用deletePreferences方法从内存中移除指定文件对应的Preferences单实例,并删除指定文件及其备份文件、损坏文件。删除指定文件时,应用不允许再使用该实例进行数据操作,否则会出现数据一致性问题。删除后,数据及文件将不可恢复。
```js ```js
let proDelete = data_preferences.deletePreferences(context, 'mystore') let deletePromise = preferences.deletePreferences(context, 'mystore')
proDelete.then(() => { deletePromise.then(() => {
console.info("Deleted successfully.") console.info("Deleted successfully.")
}).catch((err) => { }).catch((err) => {
console.info("Deleted failed with err: " + err) console.info("Deleted failed with err: " + err)
......
...@@ -10,7 +10,7 @@ ...@@ -10,7 +10,7 @@
## 导入模块 ## 导入模块
```ts ```ts
import data_preferences from '@ohos.data.preferences'; import preferences from '@ohos.data.preferences';
``` ```
## 常量 ## 常量
...@@ -23,7 +23,7 @@ import data_preferences from '@ohos.data.preferences'; ...@@ -23,7 +23,7 @@ import data_preferences from '@ohos.data.preferences';
| MAX_VALUE_LENGTH | string | 是 | 否 | value的最大长度限制,需小于8192字节。 | | MAX_VALUE_LENGTH | string | 是 | 否 | value的最大长度限制,需小于8192字节。 |
## data_preferences.getPreferences ## preferences.getPreferences
getPreferences(context: Context, name: string, callback: AsyncCallback&lt;Preferences&gt;): void getPreferences(context: Context, name: string, callback: AsyncCallback&lt;Preferences&gt;): void
...@@ -41,7 +41,7 @@ getPreferences(context: Context, name: string, callback: AsyncCallback&lt;Prefer ...@@ -41,7 +41,7 @@ getPreferences(context: Context, name: string, callback: AsyncCallback&lt;Prefer
**示例:** **示例:**
```ts ```ts
data_preferences.getPreferences(this.context, 'mystore', function (err, preferences) { preferences.getPreferences(this.context, 'mystore', function (err, pref) {
if (err) { if (err) {
console.info("Get preferences failed.") console.info("Get preferences failed.")
return; return;
...@@ -51,7 +51,7 @@ data_preferences.getPreferences(this.context, 'mystore', function (err, preferen ...@@ -51,7 +51,7 @@ data_preferences.getPreferences(this.context, 'mystore', function (err, preferen
``` ```
## data_preferences.getPreferences ## preferences.getPreferences
getPreferences(context: Context, name: string): Promise&lt;Preferences&gt; getPreferences(context: Context, name: string): Promise&lt;Preferences&gt;
...@@ -72,8 +72,8 @@ getPreferences(context: Context, name: string): Promise&lt;Preferences&gt; ...@@ -72,8 +72,8 @@ getPreferences(context: Context, name: string): Promise&lt;Preferences&gt;
**示例:** **示例:**
```ts ```ts
let promise = data_preferences.getPreferences(this.context, 'mystore') let promise = preferences.getPreferences(this.context, 'mystore')
promise.then((preferences) => { promise.then((pref) => {
console.info("Get preferences successfully.") console.info("Get preferences successfully.")
}).catch((err) => { }).catch((err) => {
console.info("Get preferences failed.") console.info("Get preferences failed.")
...@@ -81,7 +81,7 @@ promise.then((preferences) => { ...@@ -81,7 +81,7 @@ promise.then((preferences) => {
``` ```
## data_preferences.deletePreferences ## preferences.deletePreferences
deletePreferences(context: Context, name: string, callback: AsyncCallback&lt;void&gt;): void deletePreferences(context: Context, name: string, callback: AsyncCallback&lt;void&gt;): void
...@@ -99,7 +99,7 @@ deletePreferences(context: Context, name: string, callback: AsyncCallback&lt;voi ...@@ -99,7 +99,7 @@ deletePreferences(context: Context, name: string, callback: AsyncCallback&lt;voi
**示例:** **示例:**
```ts ```ts
data_preferences.deletePreferences(this.context, 'mystore', function (err) { preferences.deletePreferences(this.context, 'mystore', function (err) {
if (err) { if (err) {
console.info("Deleted preferences failed, err: " + err) console.info("Deleted preferences failed, err: " + err)
return return
...@@ -109,7 +109,7 @@ data_preferences.deletePreferences(this.context, 'mystore', function (err) { ...@@ -109,7 +109,7 @@ data_preferences.deletePreferences(this.context, 'mystore', function (err) {
``` ```
## data_preferences.deletePreferences ## preferences.deletePreferences
deletePreferences(context: Context, name: string): Promise&lt;void&gt; deletePreferences(context: Context, name: string): Promise&lt;void&gt;
...@@ -131,7 +131,7 @@ deletePreferences(context: Context, name: string): Promise&lt;void&gt; ...@@ -131,7 +131,7 @@ deletePreferences(context: Context, name: string): Promise&lt;void&gt;
**示例:** **示例:**
```ts ```ts
let promise = data_preferences.deletePreferences(this.context, 'mystore') let promise = preferences.deletePreferences(this.context, 'mystore')
promise.then(() => { promise.then(() => {
console.info("Deleted preferences successfully.") console.info("Deleted preferences successfully.")
}).catch((err) => { }).catch((err) => {
...@@ -140,7 +140,7 @@ promise.then(() => { ...@@ -140,7 +140,7 @@ promise.then(() => {
``` ```
## data_preferences.removePreferencesFromCache ## preferences.removePreferencesFromCache
removePreferencesFromCache(context: Context, name: string, callback: AsyncCallback&lt;void&gt;): void removePreferencesFromCache(context: Context, name: string, callback: AsyncCallback&lt;void&gt;): void
...@@ -159,7 +159,7 @@ removePreferencesFromCache(context: Context, name: string, callback: AsyncCallba ...@@ -159,7 +159,7 @@ removePreferencesFromCache(context: Context, name: string, callback: AsyncCallba
**示例:** **示例:**
```ts ```ts
data_preferences.removePreferencesFromCache(this.context, 'mystore', function (err) { 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
...@@ -169,7 +169,7 @@ data_preferences.removePreferencesFromCache(this.context, 'mystore', function (e ...@@ -169,7 +169,7 @@ data_preferences.removePreferencesFromCache(this.context, 'mystore', function (e
``` ```
## data_preferences.removePreferencesFromCache ## preferences.removePreferencesFromCache
removePreferencesFromCache(context: Context, name: string): Promise&lt;void&gt; removePreferencesFromCache(context: Context, name: string): Promise&lt;void&gt;
...@@ -192,7 +192,7 @@ removePreferencesFromCache(context: Context, name: string): Promise&lt;void&gt; ...@@ -192,7 +192,7 @@ removePreferencesFromCache(context: Context, name: string): Promise&lt;void&gt;
**示例:** **示例:**
```ts ```ts
let promise = data_preferences.removePreferencesFromCache(this.context, 'mystore') let promise = preferences.removePreferencesFromCache(this.context, 'mystore')
promise.then(() => { promise.then(() => {
console.info("Removed preferences from cache successfully.") console.info("Removed preferences from cache successfully.")
}).catch((err) => { }).catch((err) => {
...@@ -223,7 +223,7 @@ get(key: string, defValue: ValueType, callback: AsyncCallback&lt;ValueType&gt;): ...@@ -223,7 +223,7 @@ get(key: string, defValue: ValueType, callback: AsyncCallback&lt;ValueType&gt;):
**示例:** **示例:**
```ts ```ts
preferences.get('startup', 'default', function(err, value) { pref.get('startup', 'default', function(err, value) {
if (err) { if (err) {
console.info("Get value of startup failed, err: " + err) console.info("Get value of startup failed, err: " + err)
return return
...@@ -254,7 +254,7 @@ get(key: string, defValue: ValueType): Promise&lt;ValueType&gt; ...@@ -254,7 +254,7 @@ get(key: string, defValue: ValueType): Promise&lt;ValueType&gt;
**示例:** **示例:**
```ts ```ts
let promise = preferences.get('startup', 'default') let promise = pref.get('startup', 'default')
promise.then((value) => { promise.then((value) => {
console.info("Get value of startup is " + value) console.info("Get value of startup is " + value)
}).catch((err) => { }).catch((err) => {
...@@ -277,7 +277,7 @@ getAll(callback: AsyncCallback&lt;Object&gt;): void; ...@@ -277,7 +277,7 @@ getAll(callback: AsyncCallback&lt;Object&gt;): void;
**示例:** **示例:**
```ts ```ts
preferences.get.getAll(function (err, value) { pref.getAll(function (err, value) {
if (err) { if (err) {
console.info("getAll failed, err: " + err) console.info("getAll failed, err: " + err)
return return
...@@ -304,7 +304,7 @@ getAll(): Promise&lt;Object&gt; ...@@ -304,7 +304,7 @@ getAll(): Promise&lt;Object&gt;
**示例:** **示例:**
```ts ```ts
let promise = preferences.getAll() let promise = pref.getAll()
promise.then((value) => { promise.then((value) => {
let keys = Object.keys(value) let keys = Object.keys(value)
console.info('getAll keys = ' + keys) console.info('getAll keys = ' + keys)
...@@ -331,7 +331,7 @@ put(key: string, value: ValueType, callback: AsyncCallback&lt;void&gt;): void ...@@ -331,7 +331,7 @@ put(key: string, value: ValueType, callback: AsyncCallback&lt;void&gt;): void
**示例:** **示例:**
```ts ```ts
preferences.put('startup', 'auto', function (err) { pref.put('startup', 'auto', function (err) {
if (err) { if (err) {
console.info("Put value of startup failed, err: " + err) console.info("Put value of startup failed, err: " + err)
return return
...@@ -362,7 +362,7 @@ put(key: string, value: ValueType): Promise&lt;void&gt; ...@@ -362,7 +362,7 @@ put(key: string, value: ValueType): Promise&lt;void&gt;
**示例:** **示例:**
```ts ```ts
let promise = preferences.put('startup', 'auto') let promise = pref.put('startup', 'auto')
promise.then(() => { promise.then(() => {
console.info("Put value of startup successfully.") console.info("Put value of startup successfully.")
}).catch((err) => { }).catch((err) => {
...@@ -387,7 +387,7 @@ has(key: string, callback: AsyncCallback&lt;boolean&gt;): void ...@@ -387,7 +387,7 @@ has(key: string, callback: AsyncCallback&lt;boolean&gt;): void
**示例:** **示例:**
```ts ```ts
preferences.has('startup', function (err, isExist) { pref.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
...@@ -421,7 +421,7 @@ has(key: string): Promise&lt;boolean&gt; ...@@ -421,7 +421,7 @@ has(key: string): Promise&lt;boolean&gt;
**示例:** **示例:**
```ts ```ts
let promise = preferences.has('startup') let promise = pref.has('startup')
promise.then((isExist) => { promise.then((isExist) => {
if (isExist) { if (isExist) {
console.info("The key of startup is contained.") console.info("The key of startup is contained.")
...@@ -450,7 +450,7 @@ delete(key: string, callback: AsyncCallback&lt;void&gt;): void ...@@ -450,7 +450,7 @@ delete(key: string, callback: AsyncCallback&lt;void&gt;): void
**示例:** **示例:**
```ts ```ts
preferences.delete('startup', function (err) { pref.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
...@@ -480,7 +480,7 @@ delete(key: string): Promise&lt;void&gt; ...@@ -480,7 +480,7 @@ delete(key: string): Promise&lt;void&gt;
**示例:** **示例:**
```ts ```ts
let promise = preferences.delete('startup') let promise = pref.delete('startup')
promise.then(() => { promise.then(() => {
console.info("Deleted startup key successfully.") console.info("Deleted startup key successfully.")
}).catch((err) => { }).catch((err) => {
...@@ -504,7 +504,7 @@ flush(callback: AsyncCallback&lt;void&gt;): void ...@@ -504,7 +504,7 @@ flush(callback: AsyncCallback&lt;void&gt;): void
**示例:** **示例:**
```ts ```ts
preferences.flush(function (err) { pref.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
...@@ -529,7 +529,7 @@ flush(): Promise&lt;void&gt; ...@@ -529,7 +529,7 @@ flush(): Promise&lt;void&gt;
**示例:** **示例:**
```ts ```ts
let promise = preferences.flush() let promise = pref.flush()
promise.then(() => { promise.then(() => {
console.info("Flushed to file successfully.") console.info("Flushed to file successfully.")
}).catch((err) => { }).catch((err) => {
...@@ -553,7 +553,7 @@ clear(callback: AsyncCallback&lt;void&gt;): void ...@@ -553,7 +553,7 @@ clear(callback: AsyncCallback&lt;void&gt;): void
**示例:** **示例:**
```ts ```ts
preferences.clear(function (err) { pref.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
...@@ -578,7 +578,7 @@ clear(): Promise&lt;void&gt; ...@@ -578,7 +578,7 @@ clear(): Promise&lt;void&gt;
**示例:** **示例:**
```ts ```ts
let promise = preferences.clear() let promise = pref.clear()
promise.then(() => { promise.then(() => {
console.info("Cleared to file successfully.") console.info("Cleared to file successfully.")
}).catch((err) => { }).catch((err) => {
...@@ -607,17 +607,15 @@ var observer = function (key) { ...@@ -607,17 +607,15 @@ var observer = function (key) {
console.info("The key of " + key + " changed.") console.info("The key of " + key + " changed.")
} }
... pref.on('change', observer)
pref.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) { pref.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
...@@ -648,23 +646,21 @@ var observer = function (key) { ...@@ -648,23 +646,21 @@ var observer = function (key) {
console.info("The key of " + key + " changed.") console.info("The key of " + key + " changed.")
} }
... pref.on('change', observer)
pref.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) { pref.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.") // observer will be called. console.info("Flushed to file successfully.") // observer will be called.
preferences.off('change', observer) pref.off('change', observer)
}) })
}) })
``` ```
...@@ -675,8 +671,11 @@ preferences.put('startup', 'auto', function (err) { ...@@ -675,8 +671,11 @@ preferences.put('startup', 'auto', function (err) {
**系统能力:** SystemCapability.DistributedDataManager.Preferences.Core **系统能力:** SystemCapability.DistributedDataManager.Preferences.Core
| 名称 | 说明 | | 名称 | 说明 |
| ------- | -------------------- | | ------------- | ---------------------- |
| number | 表示值类型为数字。 | | number | 表示值类型为数字。 |
| string | 表示值类型为字符。 | | string | 表示值类型为字符。 |
| boolean | 表示值类型为布尔值。 | | boolean | 表示值类型为布尔值。 |
| Array<number> | 表示值类型为数字数组。 |
| Array<string> | 表示值类型为字符数组。 |
| Array<bool> | 表示值类型为布尔数组。 |
...@@ -49,7 +49,7 @@ getStorageSync(path: string): Storage ...@@ -49,7 +49,7 @@ getStorageSync(path: string): Storage
import dataStorage from '@ohos.data.storage' import dataStorage from '@ohos.data.storage'
import featureAbility from '@ohos.ability.featureAbility' import featureAbility from '@ohos.ability.featureAbility'
var context = featureAbility.getContext() var path = '/data/storage/el2/database/test_storage'
context.getFilesDir((err, path) => { context.getFilesDir((err, path) => {
if (err) { if (err) {
console.error('getFilesDir failed. err: ' + JSON.stringify(err)); console.error('getFilesDir failed. err: ' + JSON.stringify(err));
...@@ -82,7 +82,7 @@ getStorage(path: string, callback: AsyncCallback&lt;Storage&gt;): void ...@@ -82,7 +82,7 @@ getStorage(path: string, callback: AsyncCallback&lt;Storage&gt;): void
import dataStorage from '@ohos.data.storage' import dataStorage from '@ohos.data.storage'
import featureAbility from '@ohos.ability.featureAbility' import featureAbility from '@ohos.ability.featureAbility'
var context = featureAbility.getContext() var path = '/data/storage/el2/database/test_storage'
context.getFilesDir((err, path) => { context.getFilesDir((err, path) => {
if (err) { if (err) {
console.error('getFilesDir failed. err: ' + JSON.stringify(err)); console.error('getFilesDir failed. err: ' + JSON.stringify(err));
...@@ -124,7 +124,7 @@ getStorage(path: string): Promise&lt;Storage&gt; ...@@ -124,7 +124,7 @@ getStorage(path: string): Promise&lt;Storage&gt;
import dataStorage from '@ohos.data.storage' import dataStorage from '@ohos.data.storage'
import featureAbility from '@ohos.ability.featureAbility' import featureAbility from '@ohos.ability.featureAbility'
var context = featureAbility.getContext() var path = '/data/storage/el2/database/test_storage'
context.getFilesDir((err, path) => { context.getFilesDir((err, path) => {
if (err) { if (err) {
console.info("Get the storage failed, path: " + path + '/mystore') console.info("Get the storage failed, path: " + path + '/mystore')
......
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