HarmonyOS EntryAbility中的onForeground方法中设置PrivacyMode无效，如何为退到后台的应用添加毛玻璃效果？

当前实现毛玻璃效果可以通过监听页面状态，然后设置 .blur(this.val) 的方式实现，该方法是需要页面单独处理，可以针对需要处理的页面去实现

import { common } from '@kit.AbilityKit';
import { window } from '@kit.ArkUI';

@Entry
@Component
struct Index {
  @State message: string = 'Hello World';
  @State val:number = 0

  aboutToAppear(): void {
    (getContext() as common.UIAbilityContext).windowStage.on("windowStageEvent",(data)=>{
      if (data == 6) {
        this.val = 100
      }else if (data == 5){
        this.val = 0
      }
    })
  }

  build() {
    RelativeContainer() {
      Text(this.message)
        .id('HelloWorld')
        .fontSize(50)
        .fontWeight(FontWeight.Bold)
        .alignRules({
          center: { anchor: '__container__', align: VerticalAlign.Center },
          middle: { anchor: '__container__', align: HorizontalAlign.Center }
        })
    }
    .blur(this.val)
    .height('100%')
    .width('100%')
  }
}

• ArkUI子章节1

• ArkUI子章节2