如何实现通过侧滑手势关闭打开的悬浮框
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在页面的onBackPress()生命周期函数中隐藏子窗口。示例如下：

1.  在EntryAbility的onWindowStageCreate方法中创建子窗口。
    
    onWindowStageCreate(windowStage: window.WindowStage): void {
     _ // Create application subwindow_
      let windowClass: window.Window | undefined = undefined;
      windowStage.createSubWindow('mySubWindow', (err: BusinessError, data) => {
        if (err.code) {
          console.error(\`Failed to create the subwindow. Cause code: ${err.code}, message: ${err.message}\`);
          return;
        }
        windowClass = data;
        console.info('Succeeded in creating the subwindow. Data: ' + JSON.stringify(data));
        _// After the child window is created successfully, set the position, size, and related properties of the child window._
        windowClass.moveWindowTo(300, 300);
        windowClass.resize(200, 200);
        windowClass.setWindowTouchable(true);
       _ // Load the corresponding target page for the child window._
        windowClass.setUIContent('pages/Index',(err: BusinessError) => {
          if (err.code) {
            console.error(\`Failed to load the content. Cause code: ${err.code}, message: ${err.message}\`);
            return;
          }
          if (windowClass) {
            windowClass.setWindowBackgroundColor('#64b38c');
          }
        });
        (windowClass as window.Window).showWindow();
      })
      // ...
    }
    
2.  Page中使用onBackPress监听并销毁子窗口。
    
    import { window } from '@kit.ArkUI';
    
    @Entry
    @Component
    struct CloseWindowDemo {
      @State message: string = 'Hello World';
    
      onBackPress(): boolean | void {
        console.log('Triggered');
        const subWindow = window.findWindow('mySubWindow');
        if (subWindow) {
          subWindow.destroyWindow();
        }
        return true;
      }
    
      build() {
        RelativeContainer() {
          Text(this.message)
            .id('HelloWorld')
            .fontSize(20)
            .fontWeight(FontWeight.Bold)
            .alignRules({
              center: { anchor: '\_\_container\_\_', align: VerticalAlign.Center },
              middle: { anchor: '\_\_container\_\_', align: HorizontalAlign.Center }
            })
        }
        .height('100%')
        .width('100%')
      }
    }