每次注册回调函数时,都会返回一个监听生命周期的ID,此ID会自增+1。当超过监听上限数量2^63-1时,会返回-1。以 UIAbilityContext 中的使用为例进行说明。
import { AbilityConstant, AbilityLifecycleCallback, UIAbility, Want } from '@kit.AbilityKit';
import { hilog } from '@kit.PerformanceAnalysisKit';
import { window } from '@kit.ArkUI';
import { BusinessError } from '@kit.BasicServicesKit';
const TAG: string = '[LifecycleAbility]';
const DOMAIN_NUMBER: number = 0xFF00;
export default class LifecycleAbility extends UIAbility {
// 定义生命周期ID
lifecycleId: number = -1;
onCreate(want: Want, launchParam: AbilityConstant.LaunchParam): void {
// 定义生命周期回调对象
let abilityLifecycleCallback: AbilityLifecycleCallback = {
// 当UIAbility创建时被调用
onAbilityCreate(uiAbility) {
hilog.info(DOMAIN_NUMBER, TAG, `onAbilityCreate uiAbility.launchWant: ${JSON.stringify(uiAbility.launchWant)}`);
},
// 当窗口创建时被调用
onWindowStageCreate(uiAbility, windowStage: window.WindowStage) {
hilog.info(DOMAIN_NUMBER, TAG, `onWindowStageCreate uiAbility.launchWant: ${JSON.stringify(uiAbility.launchWant)}`);
hilog.info(DOMAIN_NUMBER, TAG, `onWindowStageCreate windowStage: ${JSON.stringify(windowStage)}`);
},
// 当窗口处于活动状态时被调用
onWindowStageActive(uiAbility, windowStage: window.WindowStage) {
hilog.info(DOMAIN_NUMBER, TAG, `onWindowStageActive uiAbility.launchWant: ${JSON.stringify(uiAbility.launchWant)}`);
hilog.info(DOMAIN_NUMBER, TAG, `onWindowStageActive windowStage: ${JSON.stringify(windowStage)}`);
},
// 当窗口处于非活动状态时被调用
onWindowStageInactive(uiAbility, windowStage: window.WindowStage) {
hilog.info(DOMAIN_NUMBER, TAG, `onWindowStageInactive uiAbility.launchWant: ${JSON.stringify(uiAbility.launchWant)}`);
hilog.info(DOMAIN_NUMBER, TAG, `onWindowStageInactive windowStage: ${JSON.stringify(windowStage)}`);
},
// 当窗口被销毁时被调用
onWindowStageDestroy(uiAbility, windowStage: window.WindowStage) {
hilog.info(DOMAIN_NUMBER, TAG, `onWindowStageDestroy uiAbility.launchWant: ${JSON.stringify(uiAbility.launchWant)}`);
hilog.info(DOMAIN_NUMBER, TAG, `onWindowStageDestroy windowStage: ${JSON.stringify(windowStage)}`);
},
// 当UIAbility被销毁时被调用
onAbilityDestroy(uiAbility) {
hilog.info(DOMAIN_NUMBER, TAG, `onAbilityDestroy uiAbility.launchWant: ${JSON.stringify(uiAbility.launchWant)}`);
},
// 当UIAbility从后台转到前台时触发回调
onAbilityForeground(uiAbility) {
hilog.info(DOMAIN_NUMBER, TAG, `onAbilityForeground uiAbility.launchWant: ${JSON.stringify(uiAbility.launchWant)}`);
},
// 当UIAbility从前台转到后台时触发回调
onAbilityBackground(uiAbility) {
hilog.info(DOMAIN_NUMBER, TAG, `onAbilityBackground uiAbility.launchWant: ${JSON.stringify(uiAbility.launchWant)}`);
},
// 当UIAbility迁移时被调用
onAbilityContinue(uiAbility) {
hilog.info(DOMAIN_NUMBER, TAG, `onAbilityContinue uiAbility.launchWant: ${JSON.stringify(uiAbility.launchWant)}`);
}
};
// 获取应用上下文
let applicationContext = this.context.getApplicationContext();
try {
// 注册应用内生命周期回调
this.lifecycleId = applicationContext.on('abilityLifecycle', abilityLifecycleCallback);
} catch (err) {
let code = (err as BusinessError).code;
let message = (err as BusinessError).message;
hilog.error(DOMAIN_NUMBER, TAG, `Failed to register applicationContext. Code is ${code}, message is ${message}`);
}
hilog.info(DOMAIN_NUMBER, TAG, `register callback number: ${this.lifecycleId}`);
}
//...
onDestroy(): void {
// 获取应用上下文
let applicationContext = this.context.getApplicationContext();
try {
// 取消应用内生命周期回调
applicationContext.off('abilityLifecycle', this.lifecycleId);
} catch (err) {
let code = (err as BusinessError).code;
let message = (err as BusinessError).message;
hilog.error(DOMAIN_NUMBER, TAG, `Failed to unregister applicationContext. Code is ${code}, message is ${message}`);
}
}
}
文档链接:https://developer.huawei.com/consumer/cn/doc/harmonyos-guides-V5/application-context-stage-V5