HarmonyOS鸿蒙Next中onAbilityBackground执行异步方法不生效，比如保存数据到perference里

HarmonyOS鸿蒙Next中onAbilityBackground执行异步方法不生效，比如保存数据到perference里

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 AbilityLifecycleCallback from '@ohos.app.ability.AbilityLifecycleCallback';

export default class EntryAbility extends UIAbility {
  lifecycleId: number;

  onCreate(want: Want, launchParam: AbilityConstant.LaunchParam): void {
    hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onCreate');
    // 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(0x0000, 'testTag', '%{public}s', `onAbilityCreate uiAbility.launchWant: ${JSON.stringify(uiAbility.launchWant)}`);
      },
      // 当窗口创建时被调用
      onWindowStageCreate(uiAbility, windowStage: window.WindowStage) {
        hilog.info(0x0000, 'testTag', '%{public}s', `onWindowStageCreate uiAbility.launchWant: ${JSON.stringify(uiAbility.launchWant)}`);
        hilog.info(0x0000, 'testTag', '%{public}s', `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(0x0000, 'testTag', '%{public}s', `onWindowStageActive uiAbility.launchWant: ${JSON.stringify(uiAbility.launchWant)}`);
        hilog.info(0x0000, 'testTag', '%{public}s', `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(0x0000, 'testTag', '%{public}s', `onWindowStageInactive uiAbility.launchWant: ${JSON.stringify(uiAbility.launchWant)}`);
        hilog.info(0x0000, 'testTag', '%{public}s', `onWindowStageInactive windowStage: ${JSON.stringify(windowStage)}`);
      },
      // 当窗口被销毁时被调用
      onWindowStageDestroy(uiAbility, windowStage: window.WindowStage) {
        hilog.info(0x0000, 'testTag', '%{public}s', `onWindowStageDestroy uiAbility.launchWant: ${JSON.stringify(uiAbility.launchWant)}`);
        hilog.info(0x0000, 'testTag', '%{public}s', `onWindowStageDestroy windowStage: ${JSON.stringify(windowStage)}`);
      },
      // 当UIAbility被销毁时被调用
      onAbilityDestroy(uiAbility) {
        hilog.info(0x0000, 'testTag', '%{public}s', `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(0x0000, 'testTag', '%{public}s', `onAbilityForeground uiAbility.launchWant: ${JSON.stringify(uiAbility.launchWant)}`);
      },
      // 当UIAbility从前台转到后台时触发回调
      async onAbilityBackground(uiAbility) {
        hilog.info(0x0000, 'testTag', '%{public}s', `onAbilityBackground uiAbility.launchWant: ${JSON.stringify(uiAbility.launchWant)}`);
        hilog.info(0x0000, 'testTag', '%{public}s', `onAbilityBackground wait start`);
        await this.wait(1000);
        hilog.info(0x0000, 'testTag', '%{public}s', `onAbilityBackground wait end`);
      },
      // 当UIAbility迁移时被调用
      onAbilityContinue(uiAbility) {
        hilog.info(0x0000, 'testTag', '%{public}s', `onAbilityContinue uiAbility.launchWant: ${JSON.stringify(uiAbility.launchWant)}`);
      }
    }
    // 获取应用上下文
    let applicationContext = this.context.getApplicationContext();
    // 注册应用内生命周期回调
    this.lifecycleId = applicationContext.on('abilityLifecycle', abilityLifecycleCallback);
    hilog.info(0x0000, 'testTag', '%{public}s', `register callback number: ${this.lifecycleId}`);
  }

  // 函数实现，参数单位 毫秒 ；
  async wait(ms:number) {
    await this.sleep(ms);
  }

  sleep(ms:number):Promise<void> {
    return new Promise<void>(resolve => setTimeout(() => resolve(), ms));
  }

  onDestroy(): void {
    hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onDestroy');
  }

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

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

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