HarmonyOS @Entry页面设置透明背景怎么处理

router路由模式请参考下面demo：

// Page1.ets
import window from '@ohos.window';

@Entry
@Component
struct Page2 {
  @State message: string = 'page Page2';

  onPageHide() {
    console.log("pageHide")
  }

  build() {
    Row() {
      Column() {
        Text(this.message)
          .fontSize(50)
          .fontWeight(FontWeight.Bold)
        Button("pageB").onClick(() => {
          let windowStege: window.WindowStage = AppStorage.get("windowStage") as window.WindowStage;
          windowStege.createSubWindow("hello", (err, win) => {
            win.setUIContent('pages/Page2');
            win.showWindow();
          })
        })
      }
      .width('100%')
    }
    .height('100%')
    .backgroundColor(Color.Pink)
  }
}

// Page2.ets
import window from '@ohos.window';

@Entry
@Component
struct Index {
  @State message: string = 'page Index';

  aboutToAppear() {
    window.findWindow("hello").setWindowBackgroundColor("#00000000")
  }

  onBackPress() {
    window.findWindow("hello").destroyWindow().then((res) => {
      console.log("destroyWindow success")
    }).catch(() => {
      console.log("destroyWindow fail")
    })
    return true
  }

  build() {
    Row() {
      Column() {
        Text(this.message)
          .fontSize(50)
          .fontWeight(FontWeight.Bold)
      }
      .width('100%')
      .backgroundColor(Color.Red)
    }
    .alignItems(VerticalAlign.Top)
    .height('100%')
    .backgroundColor("#80ffffff")
  }
}

//注意需要在EntryAbility里面添加关键代码那一行
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/Page231206095213071', (err, data) => {
  if (err.code) {
  hilog.error(0x0000, 'testTag', 'Failed to load the content. Cause: %{public}s', JSON.stringify(err) ?? '');
  return;
}
AppStorage.setAndLink("windowStage", windowStage);// 关键代码
hilog.info(0x0000, 'testTag', 'Succeeded in loading the content. Data: %{public}s', JSON.stringify(data) ?? '');
});
}

AppStorage.setAndLink(“windowStage”, windowStage);// 关键代码 只需要看这行的关键代码就可以了，这个是配置windowStage.loadContent(‘pages/page1’) ，这个demo是page1跳转page2,page2是透明的效果