如何实现图片的大图预览效果

@Entry 
@Component 
struct Index { 
  @State visible: Visibility = Visibility.None 
  @State scaleValue: number = 1 
  @State pinchValue: number = 1 
  @State pinchX: number = 0 
  @State pinchY: number = 0 
  @State count: number = 0 
  @State offsetX: number = 0 
  @State offsetY: number = 0 
  @State positionX: number = 0 
  @State positionY: number = 0 
 
  build() { 
    Stack() { 
      Row() { 
        Column() { 
          Image($r('app.media.icon')) 
            .width(100) 
            .height(100) 
            .onClick(() => { 
              console.log("hit me!") 
              if (this.visible == Visibility.Visible) { 
                this.visible = Visibility.None 
              } else { 
                this.visible = Visibility.Visible 
              } 
            }) 
        } 
        .width('100%') 
        .justifyContent(FlexAlign.Center) 
        .alignItems(HorizontalAlign.Center) 
      } 
      .height('100%') 
 
 
      Text('') 
        .onClick(() => { 
          if (this.visible == Visibility.Visible) { 
            this.visible = Visibility.None 
          } else { 
            this.visible = Visibility.Visible 
          } 
        }) 
        .width('100%') 
        .height('100%')// 透明度可以自己调节一下 
        .opacity(0.16) 
        .backgroundColor(0x000000) 
        .visibility(this.visible) 
 
      Column() { 
        Image($r('app.media.icon')) 
          .width(300) 
          .height(300) 
          .draggable(false) 
          .visibility(this.visible) 
          .scale({ x: this.scaleValue, y: this.scaleValue, z: 1 }) 
          .translate({ x: this.offsetX, y: this.offsetY, z: 0 }) 
 
          .gesture( 
            GestureGroup(GestureMode.Parallel, 
              PinchGesture({ fingers: 2 }) 
                .onActionStart((event?: GestureEvent) => { 
                  console.info('Pinch start') 
                }) 
                .onActionUpdate((event?: GestureEvent) => { 
                  if (event) { 
                    this.scaleValue = this.pinchValue * event.scale 
                    this.pinchX = event.pinchCenterX 
                    this.pinchY = event.pinchCenterY 
                  } 
                }) 
                .onActionEnd(() => { 
                  this.pinchValue = this.scaleValue 
                  console.info('Pinch end') 
                }), 
 
              PanGesture() 
                .onActionUpdate((event?: GestureEvent) => { 
                  if (event) { 
                    this.offsetX = this.positionX + event.offsetX 
                    this.offsetY = this.positionY + event.offsetY 
                  } 
                  console.info('pan update') 
                }) 
                .onActionEnd(() => { 
                  this.positionX = this.offsetX 
                  this.positionY = this.offsetY 
                  console.info('pan end') 
                }) 
            ) 
 
          ) 
 
      } 
    } 
 
  } 
}