HarmonyOS如何将Component转换PixelMap？

@Entry  
@Component  
struct CanvasExample2 {  
//用来配置CanvasRenderingContext2D对象和OffscreenCanvasRenderingContext2D对象的参数，包括是否开启抗锯齿。true表明开启抗锯齿  
  private settings: RenderingContextSettings = new RenderingContextSettings(true)  
  private context: CanvasRenderingContext2D = new CanvasRenderingContext2D(this.settings)  
//用来创建OffscreenCanvasRenderingContext2D对象，width为离屏画布的宽度，height为离屏画布的高度。通过在canvas中调用OffscreenCanvasRenderingContext2D对象来绘制。  
  private offContext: OffscreenCanvasRenderingContext2D = new OffscreenCanvasRenderingContext2D(600, 600, this.settings)  
  build() {  
    Flex({ direction: FlexDirection.Column, alignItems: ItemAlign.Center, justifyContent: FlexAlign.Center }) {  
      Canvas(this.context)  
        .width('100%')  
        .height('100%')  
        .backgroundColor('#F5DC62')  
        .onReady(() =>{  
          //可以在这里绘制内容  
          this.offContext.strokeRect(50, 50, 200, 150);  
          //将离屏绘值渲染的图像在普通画布上显示  
          let image = this.offContext.transferToImageBitmap();  
          this.context.transferFromImageBitmap(image);  
        })  
    }  
    .width('100%')  
    .height('100%')  
  }  
}