---

一、數據持久化

1、用戶首選項

（1）語法說明

• 為應用提供Key-Value鍵值型的數據處理能力，支持應用持久化輕量級數據，并對其修改和查詢。
• Key鍵為string類型，要求非空且長度不超過80個字節。
• 如果Value值為string類型，可以為空，不為空時長度不超過8192個字節。
• 建議存儲的數據不超過一萬條。
• 導入用戶首選項模塊

import dataPreferences from '@ohos.data.preferences';

• 要獲取Preferences實例，讀取指定文件

 dataPreferences.getPreferences(this.context, 'mystore', (err, preferences) => {if (err) {console.error(`Failed to get preferences. Code:${err.code},message:${err.message}`);return;}console.info('Succeeded in getting preferences.');// 進行相關數據操作})

• 數據操作
• 寫入數據，如果已經存在則會覆蓋，可利用.has() 判斷是否存在

 preferences.put('startup', 'auto', (err) => {if (err) {console.error(`Failed to put data. Code:${err.code}, message:${err.message}`);return;}console.info('Succeeded in putting data.');})

• 讀取數據，如果值為null或者非默認值類型，則返回默認數據。

 preferences.get('startup', 'default', (err, val) => {if (err) {console.error(`Failed to get value of 'startup'. Code:${err.code}, message:${err.message}`);return;}console.info(`Succeeded in getting value of 'startup'. val: ${val}.`);})

• 刪除數據

  preferences.delete('startup', (err) => {if (err) {console.error(`Failed to delete the key 'startup'. Code:${err.code}, message:${err.message}`);return;}console.info("Succeeded in deleting the key 'startup'.");})

• 數據持久化，應用存入數據到Preferences實例后，可以使用flush()方法實現數據持久化

preferences.flush((err) => {if (err) {console.error(`Failed to flush. Code:${err.code}, message:${err.message}`);return;}console.info('Succeeded in flushing.');})

（2）完整代碼示例

• ets/common/util/PreferencesUtil.ts
• 加載實例、寫入、獲取、刪除方法

import preferences from '@ohos.data.preferences';class PreferencesUtil{prefMap: Map<string, preferences.Preferences> = new Map()async loadPreference(context, name: string){try { // 加載preferenceslet pref = await preferences.getPreferences(context, name)this.prefMap.set(name, pref)console.log('testTag', `加載Preferences[${name}]成功`)} catch (e) {console.log('testTag', `加載Preferences[${name}]失敗`, JSON.stringify(e))}}async putPreferenceValue(name: string, key: string, value: preferences.ValueType){if (!this.prefMap.has(name)) {console.log('testTag', `Preferences[${name}]尚未初始化！`)return}try {let pref = this.prefMap.get(name)// 寫入數據await pref.put(key, value)// 刷盤await pref.flush()console.log('testTag', `保存Preferences[${name}.${key} = ${value}]成功`)} catch (e) {console.log('testTag', `保存Preferences[${name}.${key} = ${value}]失敗`, JSON.stringify(e))}}async getPreferenceValue(name: string, key: string, defaultValue: preferences.ValueType){if (!this.prefMap.has(name)) {console.log('testTag', `Preferences[${name}]尚未初始化！`)return}try {let pref = this.prefMap.get(name)// 讀數據let value = await pref.get(key, defaultValue)console.log('testTag', `讀取Preferences[${name}.${key} = ${value}]成功`)return value} catch (e) {console.log('testTag', `讀取Preferences[${name}.${key} ]失敗`, JSON.stringify(e))}}
}const preferencesUtil = new PreferencesUtil()export default preferencesUtil as PreferencesUtil

• ets/entryability/EntryAbility.ets
• 應用啟動時調用加載實例方法

import UIAbility from '@ohos.app.ability.UIAbility';
import PreferencesUtil from '../common/util/PreferencesUtil'export default class EntryAbility extends UIAbility {async onCreate(want, launchParam) {hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onCreate running');// 加載Preferencesawait PreferencesUtil.loadPreference(this.context, 'MyPreferences')}
}

• ets/pages/Index.ets
• 頁面出現前（aboutToAppear()）獲取實例并賦值

import IndexFontSizePanel from '../views/IndexFontSizePanel'
import PreferencesUtil from '../common/util/PreferencesUtil'@Entry
@Component
struct Index {@State message: string = '頁面列表'@State showPanel: boolean = false@Provide fontSize: number = 16async aboutToAppear(){this.fontSize = await PreferencesUtil.getPreferenceValue('MyPreferences', 'IndexFontSize', 16) as number}build() {Column() {// 字體修改面板if(this.showPanel){IndexFontSizePanel().transition({translate: { y: 115 }})}}.width('100%').height('100%')}}

• views/IndexFontSizePanel.ets
• onChange 方法中修改實例值

import PreferencesUtil from '../common/util/PreferencesUtil'@Component
export default struct IndexFontSizePanel {@Consume fontSize: numberfontSizLabel: object = {14: '小',16: '標準',18: '大',20: '特大',}build() {Column() {Text(this.fontSizLabel[this.fontSize]).fontSize(20)Row({ space: 5 }) {Text('A').fontSize(14).fontWeight(FontWeight.Bold)Slider({min: 14,max: 20,step: 2,value: this.fontSize}).showSteps(true).trackThickness(6).layoutWeight(1).onChange(val => {// 修改字體大小this.fontSize = val// 寫入PreferencesPreferencesUtil.putPreferenceValue('MyPreferences', 'IndexFontSize', val)})Text('A').fontSize(20).fontWeight(FontWeight.Bold)}.width('100%')}.width('100%').padding(15).backgroundColor('#fff1f0f0').borderRadius(20)}
}

2、關系型數據庫

（1）初始化數據庫

• a、導入關系型數據庫模塊

import relationalStore from '@ohos.data.relationalStore';

• b、初始化數據庫表
• rdb配置

const STORE_CONFIG = {name: 'RdbTest.db', // 數據庫文件名securityLevel: relationalStore.SecurityLevel.S1 // 數據庫安全級別
};

• 初始化表的SQL

// 建表Sql語句
const SQL_CREATE_TABLE = 'CREATE TABLE IF NOT EXISTS EMPLOYEE (ID INTEGER PRIMARY KEY AUTOINCREMENT, NAME TEXT NOT NULL, AGE INTEGER, SALARY REAL, CODES BLOB)';

• 獲取rdb,執行SQL,后續的所有增刪改查都是使用rdbStore對象

relationalStore.getRdbStore(this.context, STORE_CONFIG, (err, store) => {if (err) {console.error(`Failed to get RdbStore. Code:${err.code}, message:${err.message}`);return;}console.info(`Succeeded in getting RdbStore.`);store.executeSql(SQL_CREATE_TABLE); // 創建數據表// 這里執行數據庫的增、刪、改、查等操作});

（2）增刪改數據

• a.新增數據

const valueBucket = {'NAME': 'Lisa','AGE': 18,'SALARY': 100.5,'CODES': new Uint8Array([1, 2, 3, 4, 5])
};
//EMPLOYEE 數據表名
store.insert('EMPLOYEE', valueBucket, (err, rowId) => {if (err) {console.error(`Failed to insert data. Code:${err.code}, message:${err.message}`);return;}console.info(`Succeeded in inserting data. rowId:${rowId}`);
})

• b.修改數據

const valueBucket = {'NAME': 'Rose','AGE': 22,
};
// 創建表'EMPLOYEE'的predicates
let predicates = new relationalStore.RdbPredicates('EMPLOYEE');
// 匹配表'EMPLOYEE'中'NAME'為'Lisa'的字段
predicates.equalTo('NAME', 'Lisa'); 
store.update(valueBucket, predicates, (err, rows) => {if (err) {console.error(`Failed to update data. Code:${err.code}, message:${err.message}`);return;}console.info(`Succeeded in updating data. row count: ${rows}`);
})

• c.刪除數據

let predicates = new relationalStore.RdbPredicates('EMPLOYEE');
predicates.equalTo('NAME', 'Lisa');
store.delete(predicates, (err, rows) => {if (err) {console.error(`Failed to delete data. Code:${err.code}, message:${err.message}`);return;}console.info(`Delete rows: ${rows}`);
})

（3）查詢數據

• a.查詢數據、返回一個ResultSet結果集

let predicates = new relationalStore.RdbPredicates('EMPLOYEE');
predicates.equalTo('NAME', 'Rose');
let result = await store.query(predicates, ['ID', 'NAME', 'AGE', 'SALARY', 'CODES'])

• b.解析結果

// 準備數組保存結果
let tasks:any[]=[]
//循環遍歷結果集，判斷結果是否遍歷到最后一行
while(!result.isAtLastRow){//指針移動到下一行數據result.goToNextRow()//根據字段名獲取字段index，從而獲取字段值let id = result.getLong(result.getColumnIndex('ID'));let name = result.getString(result.getColumnIndex('NAME'));tasks.push({id,name})
}

（4）完整代碼示例

• ets/model/TaskModel.ets

import relationalStore from '@ohos.data.relationalStore';
import TaskInfo from '../viewmodel/TaskInfo';class TaskModel {private rdbStore: relationalStore.RdbStoreprivate tableName: string = 'TASK'/*** 初始化任務表*/initTaskDB(context){// 1.rdb配置const config = {name: 'MyApplication.db',securityLevel: relationalStore.SecurityLevel.S1}// 2.初始化SQL語句const sql = `CREATE TABLE IF NOT EXISTS TASK (ID INTEGER PRIMARY KEY AUTOINCREMENT,NAME TEXT NOT NULL,FINISHED bit)`// 3.獲取rdbrelationalStore.getRdbStore(context, config, (err, rdbStore) => {if(err){console.log('testTag', '獲取rdbStore失敗！')return}// 執行SqlrdbStore.executeSql(sql)console.log('testTag', '創建task表成功！')// 保存rdbStorethis.rdbStore = rdbStore})}/*** 查詢任務列表*/async getTaskList(){// 1.構建查詢條件let predicates = new relationalStore.RdbPredicates(this.tableName)// 2.查詢let result = await this.rdbStore.query(predicates, ['ID', 'NAME', 'FINISHED'])// 3.解析查詢結果// 3.1.定義一個數組，組裝最終的查詢結果let tasks: TaskInfo[] = []// 3.2.遍歷封裝while(!result.isAtLastRow){// 3.3.指針移動到下一行result.goToNextRow()// 3.4.獲取數據let id = result.getLong(result.getColumnIndex('ID'))let name = result.getString(result.getColumnIndex('NAME'))let finished = result.getLong(result.getColumnIndex('FINISHED'))// 3.5.封裝到數組tasks.push({id, name, finished: !!finished})}console.log('testTag', '查詢到數據：', JSON.stringify(tasks))return tasks}/*** 添加一個新的任務* @param name 任務名稱* @returns 任務id*/addTask(name: string): Promise<number>{return this.rdbStore.insert(this.tableName, {name, finished: false})}/*** 根據id更新任務狀態* @param id 任務id* @param finished 任務是否完成*/updateTaskStatus(id: number, finished: boolean) {// 1.要更新的數據let data = {finished}// 2.更新的條件let predicates = new relationalStore.RdbPredicates(this.tableName)predicates.equalTo('ID', id)// 3.更新操作return this.rdbStore.update(data, predicates)}/*** 根據id刪除任務* @param id 任務id*/deleteTaskById(id: number){// 1.刪除的條件let predicates = new relationalStore.RdbPredicates(this.tableName)predicates.equalTo('ID', id)// 2.刪除操作return this.rdbStore.delete(predicates)}
}let taskModel = new TaskModel();export default taskModel as TaskModel;

• ets/entryability/EntryAbility.ets
• 應用啟動時調用初始化

import UIAbility from '@ohos.app.ability.UIAbility';
import hilog from '@ohos.hilog';
import window from '@ohos.window';
import TaskModel from '../model/TaskModel';export default class EntryAbility extends UIAbility {async onCreate(want, launchParam) {// 初始化任務表TaskModel.initTaskDB(this.context)}
}

• 頁面調用方法查詢、添加數據

import TaskModel from '../../model/TaskModel'// 總任務數量@Link totalTask: number@Link finishTask: number// 任務數組@State tasks: TaskInfo[] = []aboutToAppear(){// 查詢任務列表console.log('testTag', '初始化組件，查詢任務列表')TaskModel.getTaskList().then(tasks => {this.tasks = tasks// 更新任務狀態this.handleTaskChange()})}handleTaskChange(){// 1.更新任務總數量this.totalTask = this.tasks.length// 2.更新已完成任務數量this.finishTask = this.tasks.filter(item => item.finished).length}

  handleAddTask(name: string){// 1.新增任務TaskModel.addTask(name).then(id => {console.log('testTag', '處理新增任務: ', name)// 回顯到數組頁面this.tasks.push(new TaskInfo(id, name))// 2.更新任務完成狀態this.handleTaskChange()// 3.關閉對話框this.dialogController.close()}).catch(error => console.log('testTag', '新增任務失敗：', name, JSON.stringify(error)))}

@Builder DeleteButton(index: number, id: number){Button(){Image($r('app.media.ic_public_delete_filled')).fillColor(Color.White).width(20)}.width(40).height(40).type(ButtonType.Circle).backgroundColor(Color.Red).margin(5).onClick(() => {// 刪除任務TaskModel.deleteTaskById(id).then(() => {this.tasks.splice(index, 1)console.log('testTag', `嘗試刪除任務，index: ${index}`)this.handleTaskChange()}).catch(error => console.log('testTag', '刪除任務失敗，id = ', id, JSON.stringify(error)))})}

二、通知

1、基礎通知

• 應用可以通過通知接口發送通知消息，提醒用戶關注應用中變化。
• 用戶可以在通知欄查看和操作通知內容

（1）基礎使用

• 導入notification模塊

import notificationManager from '@ohos.notificationManager';

• 構建通知請求

let request: notificationManager.NotificationRequest = {id: 1, content: {// 通知內容：...}},showDeliveryTime: true, // 是否顯示分發時間deliveryTime: new Date().getTime(), // 通知發送時間groupName: 'wechat', // 組通知名稱slotType: notify.SlotType.SOCIAL_COMMUNICATION  // 通道類型...   //其它屬性查看相關文檔
}

• 發布通知

notificationManager.publish(request, (err) => {if (err) {console.error(`Failed to publish notification. Code is ${err.code}, message is ${err.message}`);return;}console.info('Succeeded in publishing notification.');
});

• 取消通知

// 取消 id=10 的通知
notificationManager.cancel(10)
// 取消當前應用所有通知
notificationManager.cancelAll()

（2）通知內容類型

• 普通文本類型

let notificationRequest = {id: 1,content: {contentType: notificationManager.ContentType.NOTIFICATION_CONTENT_BASIC_TEXT, // 普通文本類型通知normal: {title: '通知標題',text: '通知內容詳情',additionalText: '通知附加內容',}}
}

• 長文本類型

let notificationRequest = {id: 1,content: {contentType: notificationManager.ContentType.NOTIFICATION_CONTENT_LONG_TEXT, // 長文本類型通知longText: {title: '通知標題',text: '通知內容詳情',additionalText: '通知附加內容',longText: '通知中的長文本、很長很長。。。',briefText: '通知概要總結',expandedTitle: '通知展開時的標題',}}
}

• 多行文本類型

let notificationRequest = {id: 1,content: {contentType: NotificationManager.ContentType.NOTIFICATION_CONTENT_MULTILINE, // 多行文本類型通知multiLine: {title: '通知標題',text: '通知內容詳情',additionalText: '通知附加內容',briefText: '通知概要總結',longTitle: '展開時的標題，有多行，我很寬',lines: ['第一行', '第二行', '第三行', '第四行'],}}
}

• 圖片類型

// 需要獲取圖片PixelMap信息
let imagePixelMap: PixelMap = undefined; 
let notificationRequest: notificationManager.NotificationRequest = {id: 1,content: {contentType: notificationManager.ContentType.NOTIFICATION_CONTENT_PICTURE,picture: {title: '通知標題',text: '通知內容詳情',additionalText: '通知附加內容',briefText: '通知概要總結',expandedTitle: '通知展開時的標題',picture: imagePixelMap}}
};

• 獲取圖片PixelMap信息

async aboutToAppear() {// 獲取資源管理器let rm = getContext(this).resourceManager;// 讀取圖片let file = await rm.getMediaContent($r('app.media.watchGT4'))// 創建PixelMapimage.createImageSource(file.buffer).createPixelMap().then(value => this.pixel = value).catch(reason => console.log('testTag', '加載圖片異常', JSON.stringify(reason)))
}

（3）完整代碼示例

import notify from '@ohos.notificationManager'
import image from '@ohos.multimedia.image'@Entry
@Component
struct NotificationPage {// 全局任務ididx: number = 100// 圖象pixel: PixelMapasync aboutToAppear() {// 獲取資源管理器let rm = getContext(this).resourceManager;// 讀取圖片let file = await rm.getMediaContent($r('app.media.watchGT4'))// 創建PixelMapimage.createImageSource(file.buffer).createPixelMap().then(value => this.pixel = value).catch(reason => console.log('testTag', '加載圖片異常', JSON.stringify(reason)))}build() {Column({space: 20}) {Button(`發送normalText通知`).onClick(() => this.publishNormalTextNotification())Button(`發送longText通知`).onClick(() => this.publishLongTextNotification())Button(`發送multiLine通知`).onClick(() => this.publishMultiLineNotification())Button(`發送Picture通知`).onClick(() => this.publishPictureNotification())}.width('100%').height('100%').padding(5).backgroundColor('#f1f2f3')}//通知普通文本publishNormalTextNotification() {let request: notify.NotificationRequest = {id: this.idx++,content: {contentType: notify.ContentType.NOTIFICATION_CONTENT_BASIC_TEXT,normal: {title: '通知標題' + this.idx,text: '通知內容詳情',additionalText: '通知附加內容'}},showDeliveryTime: true,deliveryTime: new Date().getTime(),groupName: 'wechat',slotType: notify.SlotType.SOCIAL_COMMUNICATION}this.publish(request)}//通知長文本publishLongTextNotification() {let request: notify.NotificationRequest = {id: this.idx++,content: {contentType: notify.ContentType.NOTIFICATION_CONTENT_LONG_TEXT,longText: {title: '通知標題' + this.idx,text: '通知內容詳情',additionalText: '通知附加內容',longText: '通知中的長文本，我很長，我很長，我很長，我很長，我很長，我很長，我很長',briefText: '通知概要和總結',expandedTitle: '通知展開時的標題' + this.idx}}}this.publish(request)}//通知多行文本publishMultiLineNotification() {let request: notify.NotificationRequest = {id: this.idx++,content: {contentType: notify.ContentType.NOTIFICATION_CONTENT_MULTILINE,multiLine: {title: '通知標題' + this.idx,text: '通知內容詳情',additionalText: '通知附加內容',briefText: '通知概要和總結',longTitle: '展開時的標題，我很寬，我很寬，我很寬',lines: ['第一行','第二行','第三行','第四行',]}}}this.publish(request)}//通知圖片類型publishPictureNotification() {let request: notify.NotificationRequest = {id: this.idx++,content: {contentType: notify.ContentType.NOTIFICATION_CONTENT_PICTURE,picture: {title: '通知標題' + this.idx,text: '通知內容詳情',additionalText: '通知附加內容',briefText: '通知概要和總結',expandedTitle: '展開后標題' + this.idx,picture: this.pixel}}}this.publish(request)}// 發送文本private publish(request: notify.NotificationRequest) {notify.publish(request).then(() => console.log('notify test', '發送通知成功')).then(reason => console.log('notify test', '發送通知失敗', JSON.stringify(reason)))}
}

2、進度條通知

• 進度條通知會展示一個動態的進度條，主要用于文件下載、長任務處理的進度顯示。

（1）基礎使用

• 判斷當前系統是否支持進度條模板

NotificationManager.isSupportTemplate('downloadTemplate').then((data) => {console.info(`[ANS] isSupportTemplate success`);let isSupportTpl: boolean = data; // isSupportTpl的值為true表示支持支持downloadTemplate模板類通知，false表示不支持// ...
}).catch((err) => {console.error(`[ANS] isSupportTemplate failed, error[${err}]`);
});

• 通知模板
• 模板名稱，必須是 downloadTemplate

let template = {name:'downloadTemplate',data: {title: '標題：',fileName: 'music.mp4', // 文件名progressValue: 30, //進度條當前值progressMaxValue:100, // 進度條最大值}
}

• 通知請求

let notificationRquest = {id: 1,slotType: notify.SlotType.OTHER_TYPES,template: template, //進度條模板content: {contentType: notify.ContentType.NOTIFICATION_CONTENT_BASIC_TEXT,normal: {title: template.data.title + template.data.fileName,text: "sendTemplate",additionalText: "30%"}},deliveryTime: new Date().getTime(),showDeliveryTime: true
}

• 發送通知，與基礎通知相同

（3）完整代碼示例

import notify from '@ohos.notificationManager'
import promptAction from '@ohos.promptAction'enum DownloadState {NOT_BEGIN = '未開始',DOWNLOADING = '下載中',PAUSE = '已暫停',FINISHED = '已完成',
}@Component
export default struct DownloadCard {// 下載進度@State progressValue: number = 0progressMaxValue: number = 100// 任務狀態@State state: DownloadState = DownloadState.NOT_BEGIN// 下載的文件名filename: string = '圣誕星.mp4'// 模擬下載的任務的idtaskId: number = -1// 通知idnotificationId: number = 999isSupport: boolean = falseasync aboutToAppear(){// 1.判斷當前系統是否支持進度條模板this.isSupport = await notify.isSupportTemplate('downloadTemplate')}build() {Row({ space: 10 }) {Image($r('app.media.ic_files_video')).width(50)Column({ space: 5 }) {Row() {Text(this.filename)Text(`${this.progressValue}%`).fontColor('#c1c2c1')}.width('100%').justifyContent(FlexAlign.SpaceBetween)Progress({value: this.progressValue,total: this.progressMaxValue,})Row({ space: 5 }) {Text(`${(this.progressValue * 0.43).toFixed(2)}MB`).fontSize(14).fontColor('#c1c2c1')Blank()if (this.state === DownloadState.NOT_BEGIN) {Button('開始').downloadButton().onClick(() => this.download())} else if (this.state === DownloadState.DOWNLOADING) {Button('取消').downloadButton().backgroundColor('#d1d2d3').onClick(() => this.cancel())Button('暫停').downloadButton().onClick(() => this.pause())} else if (this.state === DownloadState.PAUSE) {Button('取消').downloadButton().backgroundColor('#d1d2d3').onClick(() => this.cancel())Button('繼續').downloadButton().onClick(() => this.download())} else {Button('打開').downloadButton().onClick(() => this.open())}}.width('100%')}.layoutWeight(1)}.width('100%').borderRadius(20).padding(15).backgroundColor(Color.White)}cancel() {// 取消定時任務if(this.taskId > 0){clearInterval(this.taskId);this.taskId = -1}// 清理下載任務進度this.progressValue = 0// 標記任務狀態：未開始this.state = DownloadState.NOT_BEGIN// 取消通知notify.cancel(this.notificationId)}download() {// 清理舊任務if(this.taskId > 0){clearInterval(this.taskId);}// 開啟定時任務，模擬下載this.taskId = setInterval(() => {// 判斷任務進度是否達到100if(this.progressValue >= 100){// 任務完成了，應該取消定時任務clearInterval(this.taskId)this.taskId = -1// 并且標記任務狀態為已完成this.state = DownloadState.FINISHED// 發送通知this.publishDownloadNotification()return}// 模擬任務進度變更this.progressValue += 2// 發送通知this.publishDownloadNotification()}, 500)// 標記任務狀態：下載中this.state = DownloadState.DOWNLOADING}pause() {// 取消定時任務if(this.taskId > 0){clearInterval(this.taskId);this.taskId = -1}// 標記任務狀態：已暫停this.state = DownloadState.PAUSE// 發送通知this.publishDownloadNotification()}open() {promptAction.showToast({message: '功能未實現'})}publishDownloadNotification(){// 1.判斷當前系統是否支持進度條模板if(!this.isSupport){// 當前系統不支持進度條模板return}// 2.準備進度條模板的參數let template = {name: 'downloadTemplate',data: {progressValue: this.progressValue,progressMaxValue: this.progressMaxValue}}let request: notify.NotificationRequest = {id: this.notificationId,template: template,content: {contentType: notify.ContentType.NOTIFICATION_CONTENT_BASIC_TEXT,normal: {title: this.filename + ':  ' + this.state,text: '',additionalText: this.progressValue + '%'}}}// 3.發送通知notify.publish(request).then(() => console.log('test', '通知發送成功')).catch(reason => console.log('test', '通知發送失敗！', JSON.stringify(reason)))}
}@Extend(Button) function downloadButton() {.width(75).height(28).fontSize(14)
}

3、通知意圖

• 我們可以給通知或其中的按鈕設置的行為意圖（Want）
• 從而實現拉起應用組件或發布公共事件等能力。

（1）基礎使用

• 導入模塊

import NotificationManager from '@ohos.notificationManager';
import wantAgent from '@ohos.app.ability.wantAgent';

• 意圖行為信息

let wantAgentInfo = {wants: [{deviceId: '',bundleName: 'com.example.test',abilityName: 'com.example.test.MainAbility',action: '',entities: [],uri: '',parameters: {}}],operationType: wantAgent.OperationType.START_ABILITY,requestCode: 0,wantAgentFlags:[wantAgent.WantAgentFlags.CONSTANT_FLAG]
}

• 創建wantAgent實例

 // 用于保存創建成功的WantAgent對象，后續使用其完成觸發的動作。
let wantAgentObj = null;wantAgent.getWantAgent(wantAgentInfo, (err, data) => {if (err) {console.error('[WantAgent]getWantAgent err=' + JSON.stringify(err));} else {console.info('[WantAgent]getWantAgent success');wantAgentObj = data;}
});

• 通知請求

let notificationRequest = {content: {// ....},id: 1,label: 'TEST',wantAgent: wantAgentObj,
}

（2）完整代碼示例

import wantAgent, { WantAgent } from '@ohos.app.ability.wantAgent'
import promptAction from '@ohos.promptAction'@Component
export default struct DownloadCard {// 存放wantAgent實例wantAgentInstance: WantAgentasync aboutToAppear(){// 1.判斷當前系統是否支持進度條模板this.isSupport = await notify.isSupportTemplate('downloadTemplate')// 2.創建拉取當前應用的行為意圖// 2.1.創建wantInfo信息let wantInfo: wantAgent.WantAgentInfo = {wants: [{bundleName: 'com.example.myapplication',abilityName: 'EntryAbility',}],requestCode: 0,operationType: wantAgent.OperationType.START_ABILITY,wantAgentFlags: [wantAgent.WantAgentFlags.CONSTANT_FLAG]}// 2.2.創建wantAgent實例this.wantAgentInstance = await wantAgent.getWantAgent(wantInfo)}build() {···· // 同進度條通知代碼示例}open() {promptAction.showToast({message: '功能未實現'})}publishDownloadNotification(){// 1.判斷當前系統是否支持進度條模板if(!this.isSupport){// 當前系統不支持進度條模板return}// 2.準備進度條模板的參數let template = {name: 'downloadTemplate',data: {progressValue: this.progressValue,progressMaxValue: this.progressMaxValue}}let request: notify.NotificationRequest = {id: this.notificationId,template: template,// 通知意圖wantAgent: this.wantAgentInstance,content: {contentType: notify.ContentType.NOTIFICATION_CONTENT_BASIC_TEXT,normal: {title: this.filename + ':  ' + this.state,text: '',additionalText: this.progressValue + '%'}}}// 3.發送通知notify.publish(request).then(() => console.log('test', '通知發送成功')).catch(reason => console.log('test', '通知發送失敗！', JSON.stringify(reason)))}
}@Extend(Button) function downloadButton() {.width(75).height(28).fontSize(14)
}