HarmonyOS 页面如何将背景处理为透明

可参考以下思路：

1、使用自定义弹框或者半模态弹框，参考文档：https://developer.huawei.com/consumer/cn/doc/harmonyos-references-V5/ts-methods-custom-dialog-box-V5

半模态参考文档：https://developer.huawei.com/consumer/cn/doc/harmonyos-references-V5/ts-universal-attributes-sheet-transition-V5#bindsheet

2、使用创建子窗口加载pageB页面

// 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")
  }
}

//EntryAbility.ets
AppStorage.setAndLink("windowStage", windowStage);