HarmonyOS Scan Kit服务中码图生成如何添加logo图片?

@Entry 
@Component 
struct Index { 
  @State pixelMap: image.PixelMap | undefined = undefined 
  private settings: RenderingContextSettings = new RenderingContextSettings(true) 
  private context: CanvasRenderingContext2D = new CanvasRenderingContext2D(this.settings) 
  private img: ImageBitmap = new ImageBitmap("common/logo.png") 
 
  createQRCode() { 
    this.pixelMap = undefined; 
    let content: string = 'huawei'; 
    let options: generateBarcode.CreateOptions = { 
      scanType: scanCore.ScanType.QR_CODE, 
      height: 300, 
      width: 300 
    } 
    // 码图生成接口，成功返回PixelMap格式图片 
    generateBarcode.createBarcode(content, options).then((pixelMap: image.PixelMap) => { 
      this.pixelMap = pixelMap; 
      this.context.drawImage(this.pixelMap, 0, 0, 300, 300, 0, 0, 300, 300); 
      this.context.drawImage(this.img, 0, 0, 80, 80, 110, 110,80,80 ); 
    }).catch((error: BusinessError) => { 
      hilog.error(0x0001, '[generateBarcode]', 'promise error : %{public}s', JSON.stringify(error)); 
    }) 
  } 
 
  build() { 
    Column() { 
      Canvas(this.context) 
        .width(300) 
        .height(300) 
        .onReady(()=>{ 
          this.createQRCode() 
        }) 
    } 
    .width('100%') 
    .height('100%') 
    .alignItems(HorizontalAlign.Start) 
    .justifyContent(FlexAlign.Start) 
  } 
}