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鸿蒙：创建公共事件、订阅公共事件和退订公共事件

news 2025/10/16 8:42:12

1. 前言

想获取电量过低的状态、电池充电或断电状态、屏幕解锁或锁定等公共事件时，我们可以通过commonEventManager 接口实现相关能力。

2. 参考文档

https://developer.huawei.com/consumer/cn/doc/harmonyos-references/js-apis-commoneventmanagerhttps://developer.huawei.com/consumer/cn/doc/harmonyos-references/js-apis-commoneventmanager

https://developer.huawei.com/consumer/cn/doc/harmonyos-references/commoneventmanager-definitionshttps://developer.huawei.com/consumer/cn/doc/harmonyos-references/commoneventmanager-definitions

nullhttps://developer.huawei.com/consumer/cn/doc/harmonyos-guides/common-event-subscription

3. 核心思路

创建订阅信息
订阅公共事件
取消订阅

4. 核心代码

// 创建订阅
createSubscriber(): void {// 订阅者信息：配置需要监听的公共事件let subscribeInfo: commonEventManager.CommonEventSubscribeInfo = {events: ['usual.event.POWER_CONNECTED', // 设备充电事件'usual.event.BATTERY_LOW',// 电池低电量事件],};// 1. 创建订阅者commonEventManager.createSubscriber(subscribeInfo,(err: BusinessError, subscriber: commonEventManager.CommonEventSubscriber) => {if (err) {hilog.error(DOMAIN_NUMBER, TAG, `创建订阅者失败: ${err.message}`);return;}this.showDialog("创建订阅成功")hilog.info(DOMAIN_NUMBER, TAG, 'Succeeded in creating subscriber.');// 【关键】保存订阅者对象到成员变量，后续取消订阅需用到它this.subscriber = subscriber;});
}// 订阅事件
subscribe(): void {commonEventManager.subscribe(this.subscriber, (subErr, eventData) => {if (subErr) {hilog.error(DOMAIN_NUMBER, TAG, `订阅事件失败: ${subErr.message}`);return;}this.showDialog(`订阅事件触发成功：${JSON.stringify(eventData)}`)hilog.info(DOMAIN_NUMBER, TAG, `事件触发成功！数据: ${JSON.stringify(eventData)}`);});
}// 取消订阅事件
unsubscribe(): void {if (this.subscriber !== null) {commonEventManager.unsubscribe(this.subscriber, (err: BusinessError) => {if (err) {hilog.error(DOMAIN_NUMBER, TAG, `取消订阅失败: ${err.message}`);return;}this.showDialog("取消订阅成功")hilog.info(DOMAIN_NUMBER, TAG, '成功取消订阅事件');});}
}

5. 完整代码

Index.ets

import { BusinessError, commonEventManager } from '@kit.BasicServicesKit';
import { hilog } from '@kit.PerformanceAnalysisKit';const TAG: string = 'ProcessModel';
const DOMAIN_NUMBER: number = 0xFF00;@Entry
@ComponentV2
struct Index {// 【关键】将订阅者对象提升为组件成员变量，供“取消订阅”时使用private subscriber: commonEventManager.CommonEventSubscriber | null = null;// 弹窗showDialog(mes: string): void {this.getUIContext().showAlertDialog({ message: mes })}// 创建订阅createSubscriber(): void {// 订阅者信息：配置需要监听的公共事件let subscribeInfo: commonEventManager.CommonEventSubscribeInfo = {events: ['usual.event.POWER_CONNECTED', // 设备充电事件'usual.event.BATTERY_LOW',// 电池低电量事件],};// 1. 创建订阅者commonEventManager.createSubscriber(subscribeInfo,(err: BusinessError, subscriber: commonEventManager.CommonEventSubscriber) => {if (err) {hilog.error(DOMAIN_NUMBER, TAG, `创建订阅者失败: ${err.message}`);return;}this.showDialog("创建订阅成功")hilog.info(DOMAIN_NUMBER, TAG, 'Succeeded in creating subscriber.');// 【关键】保存订阅者对象到成员变量，后续取消订阅需用到它this.subscriber = subscriber;});}// 订阅事件subscribe(): void {commonEventManager.subscribe(this.subscriber, (subErr, eventData) => {if (subErr) {hilog.error(DOMAIN_NUMBER, TAG, `订阅事件失败: ${subErr.message}`);return;}this.showDialog(`订阅事件触发成功：${JSON.stringify(eventData)}`)hilog.info(DOMAIN_NUMBER, TAG, `事件触发成功！数据: ${JSON.stringify(eventData)}`);});}// 取消订阅事件unsubscribe(): void {if (this.subscriber !== null) {commonEventManager.unsubscribe(this.subscriber, (err: BusinessError) => {if (err) {hilog.error(DOMAIN_NUMBER, TAG, `取消订阅失败: ${err.message}`);return;}this.showDialog("取消订阅成功")hilog.info(DOMAIN_NUMBER, TAG, '成功取消订阅事件');});}}build() {Column({ space: 150 }) {Text("公共事件订阅示例").fontSize(20)Column({ space: 20 }) {Button("1、创建订阅事件").onClick((event: ClickEvent) => {this.createSubscriber();})Button("2、订阅事件").onClick((event: ClickEvent) => {this.subscribe();this.showDialog("订阅成功")})Button("3、取消订阅事件").onClick((event: ClickEvent) => {this.unsubscribe();})}}.height("100%").width("100%").justifyContent(FlexAlign.Center)}
}

6. 运行效果

7. 完整代码

Index.ets

import { BusinessError, commonEventManager } from '@kit.BasicServicesKit';
import { hilog } from '@kit.PerformanceAnalysisKit';const TAG: string = 'ProcessModel';
const DOMAIN_NUMBER: number = 0xFF00;@Entry
@ComponentV2
struct Index {// 【关键】将订阅者对象提升为组件成员变量，供“取消订阅”时使用private subscriber: commonEventManager.CommonEventSubscriber | null = null;// 弹窗showDialog(mes: string): void {this.getUIContext().showAlertDialog({ message: mes })}// 创建订阅createSubscriber(): void {// 订阅者信息：配置需要监听的公共事件let subscribeInfo: commonEventManager.CommonEventSubscribeInfo = {events: ['usual.event.POWER_CONNECTED', // 设备充电事件'usual.event.BATTERY_LOW',// 电池低电量事件],};// 1. 创建订阅者commonEventManager.createSubscriber(subscribeInfo,(err: BusinessError, subscriber: commonEventManager.CommonEventSubscriber) => {if (err) {hilog.error(DOMAIN_NUMBER, TAG, `创建订阅者失败: ${err.message}`);return;}this.showDialog("创建订阅成功")hilog.info(DOMAIN_NUMBER, TAG, 'Succeeded in creating subscriber.');// 【关键】保存订阅者对象到成员变量，后续取消订阅需用到它this.subscriber = subscriber;});}// 订阅事件subscribe(): void {commonEventManager.subscribe(this.subscriber, (subErr, eventData) => {if (subErr) {hilog.error(DOMAIN_NUMBER, TAG, `订阅事件失败: ${subErr.message}`);return;}this.showDialog(`订阅事件触发成功：${JSON.stringify(eventData)}`)hilog.info(DOMAIN_NUMBER, TAG, `事件触发成功！数据: ${JSON.stringify(eventData)}`);});}// 取消订阅事件unsubscribe(): void {if (this.subscriber !== null) {commonEventManager.unsubscribe(this.subscriber, (err: BusinessError) => {if (err) {hilog.error(DOMAIN_NUMBER, TAG, `取消订阅失败: ${err.message}`);return;}this.showDialog("取消订阅成功")hilog.info(DOMAIN_NUMBER, TAG, '成功取消订阅事件');});}}build() {Column({ space: 150 }) {Text("公共事件订阅示例").fontSize(20)Column({ space: 20 }) {Button("1、创建订阅事件").onClick((event: ClickEvent) => {this.createSubscriber();})Button("2、订阅事件").onClick((event: ClickEvent) => {this.subscribe();this.showDialog("订阅成功")})Button("3、取消订阅事件").onClick((event: ClickEvent) => {this.unsubscribe();})}}.height("100%").width("100%").justifyContent(FlexAlign.Center)}
}

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