监听Ability生命周期？

Question

功能场景描述及使用场景

场景：监听ability生命周期，然后在对应周期触发时，进行自定义操作，如统一日志等。

Answer 1

使用的核心API

ApplicationContext.on(type: ‘abilityLifecycle’, callback: AbilityLifecycleCallback): number；

核心代码解释

生命周期的监听只需要调用该接口传入对象参数即可，这里主要体现想要监听ability的onCreate生命周期，日常的操作都是基于ability做的，导致如果在ability里增加这个监听操作，无法监听到ability的onCreate的生命周期，这里引出AbilityStage解决该问题。

核心代码如下：

//src/main/ets/entryability/StageAbility.ets
import AbilityStage from '@ohos.app.ability.AbilityStage';
import AbilityLifecycleCallback from '@ohos.app.ability.AbilityLifecycleCallback';

// 声明ability生命周期回调，需配置所有回调后才可以在applicationContext注册
let abilityLifecycleCallback:AbilityLifecycleCallback = {
  onAbilityCreate(ability){
    console.warn(`AbilityLifecycleCallback onAbilityCreate.javaleetest ability is ${JSON.stringify(ability)}`);
  },
  onWindowStageCreate(ability, windowStage){
    console.warn(`AbilityLifecycleCallback onWindowStageCreate.javaleetest ability is ${JSON.stringify(ability)}, windowStage is is ${JSON.stringify(windowStage)}`);
  },
  onWindowStageActive(ability, windowStage){
    console.warn(`AbilityLifecycleCallback onWindowStageActive.javaleetest ability is ${JSON.stringify(ability)}, windowStage is is ${JSON.stringify(windowStage)}`);
  },
  onWindowStageInactive(ability, windowStage){
    console.warn(`AbilityLifecycleCallback onWindowStageInactive.javaleetest ability is ${JSON.stringify(ability)}, windowStage is is ${JSON.stringify(windowStage)}`);
  },
  onWindowStageDestroy(ability, windowStage){
    //
    console.warn(`AbilityLifecycleCallback onWindowStageDestroy.javaleetest ability is ${JSON.stringify(ability)}, windowStage is is ${JSON.stringify(windowStage)}`);
  },
  onAbilityDestroy(ability){
    console.warn(`AbilityLifecycleCallback onAbilityDestroy.javaleetest ability is ${JSON.stringify(ability)}`);
  },
  onAbilityForeground(ability){
    console.warn(`AbilityLifecycleCallback onAbilityForeground.javaleetest ability is ${JSON.stringify(ability)}`);
  },
  onAbilityBackground(ability){
    //
    console.warn(`AbilityLifecycleCallback onAbilityBackground.javaleetest ability is ${JSON.stringify(ability)}`);
  },
  onAbilityContinue(ability){
    console.warn(`AbilityLifecycleCallback onAbilityContinue.javaleetest ability is ${JSON.stringify(ability)}`);
  }
};

export default class StageAbility extends AbilityStage{
  public static  lifecycleId : number;
  onCreate() {
    // 1.通过context属性获取applicationContext
    let applicationContext = this.context.getApplicationContext();
    // 2.通过applicationContext注册监听应用内生命周期
    try {
      StageAbility.lifecycleId = applicationContext.on('abilityLifecycle', abilityLifecycleCallback);
      console.info(`registerAbilityLifecycleCallback lifecycleId: ${StageAbility.lifecycleId}`);
    } catch (paramError) {
      console.error(`error: ${paramError.code}, ${paramError.message}`);
    }
  }
};

//src/main/ets/entryability1/EntryAbility1.ets
import AbilityConstant from '@ohos.app.ability.AbilityConstant';
import hilog from '@ohos.hilog';
import UIAbility from '@ohos.app.ability.UIAbility';
import Want from '@ohos.app.ability.Want';
import window from '@ohos.window';
import StageAbility from '../entryability/StageAbility';

export default class EntryAbility1 extends UIAbility {
  onCreate(want: Want, launchParam: AbilityConstant.LaunchParam) {
    hilog.info(0x0000, 'AbilityLifecycleCallback', '%{public}s', 'AbilityLifecycleCallback - Ability onCreate');
  }

  onDestroy() {
    //应用退出时，通过监听创建时的返回值lifecycleId结束对ability生命周期的监听，
    let applicationContext = this.context.getApplicationContext();
    applicationContext.off("abilityLifecycle",StageAbility.lifecycleId)
    hilog.info(0x0000, 'AbilityLifecycleCallback', '%{public}s', 'Ability onDestroy');
  }

  onWindowStageCreate(windowStage: window.WindowStage) {
    // Main window is created, set main page for this ability
    hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onWindowStageCreate');
    windowStage.loadContent('pages/Index', (err, data) => {
      if (err.code) {
        hilog.error(0x0000, 'testTag', 'Failed to load the content. Cause: %{public}s', JSON.stringify(err) ?? '');
        return;
      }
      hilog.info(0x0000, 'testTag', 'Succeeded in loading the content. Data: %{public}s', JSON.stringify(data) ?? '');
    });
  }

  onWindowStageDestroy() {
    // Main window is destroyed, release UI related resources
    hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onWindowStageDestroy');
  }

  onForeground() {
    // Ability has brought to foreground
    hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onForeground');
  }

  onBackground() {
    // Ability has back to background
    hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onBackground');
  }
}

总结：

• 主要难点在于：AbilityStage不是经常用到，在应用中尝试对整体进行控制时，可以参考Stage模型所具备的上下级特征，参考：https://developer.huawei.com/consumer/cn/doc/harmonyos-guides-V2/stage-model-development-overview-0000001427744552-V2

实现效果

注明适配的版本信息

• IDE：DevEco Studio 4.0.3.600
• SDK：HarmoneyOS 4.0.10.11