import { AbilityConstant, UIAbility, Want } from '@kit.AbilityKit';export default class EntryAbility extends UIAbility {onCreate(want: Want, launchParam: AbilityConstant.LaunchParam): void {// 页面初始化}// ...
}

import { UIAbility } from '@kit.AbilityKit';
import { window } from '@kit.ArkUI';
import { hilog } from '@kit.PerformanceAnalysisKit';const TAG: string = '[EntryAbility]';
const DOMAIN_NUMBER: number = 0xFF00;export default class EntryAbility extends UIAbility {
onCreate(want: Want, launchParam: AbilityConstant.LaunchParam): void {// 页面初始化}// ...onWindowStageCreate(windowStage: window.WindowStage): void {// 设置WindowStage的事件订阅（获焦/失焦、切到前台/切到后台、前台可交互/前台不可交互）try {windowStage.on('windowStageEvent', (data) => {let stageEventType: window.WindowStageEventType = data;switch (stageEventType) {case window.WindowStageEventType.SHOWN: // 切到前台hilog.info(DOMAIN_NUMBER, TAG, `windowStage foreground.`);break;case window.WindowStageEventType.ACTIVE: // 获焦状态hilog.info(DOMAIN_NUMBER, TAG, `windowStage active.`);break;case window.WindowStageEventType.INACTIVE: // 失焦状态hilog.info(DOMAIN_NUMBER, TAG, `windowStage inactive.`);break;case window.WindowStageEventType.HIDDEN: // 切到后台hilog.info(DOMAIN_NUMBER, TAG, `windowStage background.`);break;case window.WindowStageEventType.RESUMED: // 前台可交互状态hilog.info(DOMAIN_NUMBER, TAG, `windowStage resumed.`);break;case window.WindowStageEventType.PAUSED: // 前台不可交互状态hilog.info(DOMAIN_NUMBER, TAG, `windowStage paused.`);break;default:break;}});} catch (exception) {hilog.error(DOMAIN_NUMBER, TAG,`Failed to enable the listener for window stage event changes. Cause: ${JSON.stringify(exception)}`);}hilog.info(DOMAIN_NUMBER, TAG, `%{public}s`, `Ability onWindowStageCreate`);// 设置UI加载windowStage.loadContent('pages/Index', (err, data) => {// ...});}onForeground(): void {// 申请系统需要的资源，或者重新申请在onBackground()中释放的资源}onBackground(): void {// 释放UI不可见时无用的资源，或者在此回调中执行较为耗时的操作// 例如状态保存等}
onWindowStageWillDestroy(windowStage: window.WindowStage) {// 释放通过windowStage对象获取的资源// 在onWindowStageWillDestroy()中注销WindowStage事件订阅（获焦/失焦、切到前台/切到后台、前台可交互/前台不可交互）try {if (this.windowStage) {this.windowStage.off('windowStageEvent');}} catch (err) {let code = (err as BusinessError).code;let message = (err as BusinessError).message;hilog.error(DOMAIN_NUMBER, TAG, `Failed to disable the listener for windowStageEvent. Code is ${code}, message is ${message}`);}}onWindowStageDestroy() {// 释放UI资源}onDestroy() {// 系统资源的释放、数据的保存等}
}