harmony 鸿蒙ImageData

2022-08-09
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ImageData

An ImageData object stores pixel data rendered on a canvas.

NOTE

The APIs of this module are supported since API version 8. Updates will be marked with a superscript to indicate their earliest API version.

Attributes

Name	Type	Description
width	number	Actual width of the rectangle on the canvas, in pixels. Since API version 9, this API is supported in ArkTS widgets.
height	number	Actual height of the rectangle on the canvas, in pixels. Since API version 9, this API is supported in ArkTS widgets.
data	Uint8ClampedArray	A one-dimensional array of color values. The values range from 0 to 255. Since API version 9, this API is supported in ArkTS widgets.

NOTE

You can use px2vp to convert units.

Example

  // xxx.ets
  @Entry
  @Component
  struct Translate {
    private settings: RenderingContextSettings = new RenderingContextSettings(true)
    private context: CanvasRenderingContext2D = new CanvasRenderingContext2D(this.settings)
    private img:ImageBitmap = new ImageBitmap("common/images/1234.png")

    build() {
      Flex({ direction: FlexDirection.Column, alignItems: ItemAlign.Center, justifyContent: FlexAlign.Center }) {
        Canvas(this.context)
          .width('100%')
          .height('100%')
          .backgroundColor('#ffff00')
          .onReady(() =>{
            this.context.drawImage(this.img,0,0,130,130)
            let imagedata = this.context.getImageData(50,50,130,130)
            this.context.putImageData(imagedata,150,150)
          })
      }
      .width('100%')
      .height('100%')
    }
  }

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