#创作者激励#HarmonyOS/OpenHarmony应用开发ArkTS画布组件（五）

// xxx.ets
@Entry
@Component
struct GlobalAlpha {
  private settings: RenderingContextSettings = new RenderingContextSettings(true)
  private context: CanvasRenderingContext2D = new CanvasRenderingContext2D(this.settings)
  
  build() {
    Flex({ direction: FlexDirection.Column, alignItems: ItemAlign.Center, justifyContent: FlexAlign.Center }) {
      Canvas(this.context)
        .width('100%')
        .height('100%')
        .backgroundColor('#ffff00')
        .onReady(() =>{
        this.context.fillStyle = 'rgb(0,0,255)'
        this.context.fillRect(0, 0, 50, 50)
        this.context.globalAlpha = 0.4
        this.context.fillStyle = 'rgb(0,0,255)'
        this.context.fillRect(50, 50, 50, 50)
      })
    }
    .width('100%')
    .height('100%')
  }
}

1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.

// xxx.ets
@Entry
@Component
struct LineDashOffset {
  private settings: RenderingContextSettings = new RenderingContextSettings(true)
  private context: CanvasRenderingContext2D = new CanvasRenderingContext2D(this.settings)
  
  build() {
    Flex({ direction: FlexDirection.Column, alignItems: ItemAlign.Center, justifyContent: FlexAlign.Center }) {
      Canvas(this.context)
        .width('100%')
        .height('100%')
        .backgroundColor('#ffff00')
        .onReady(() =>{
          this.context.arc(100, 75, 50, 0, 6.28)
          this.context.setLineDash([10,20])
          this.context.lineDashOffset = 10.0
          this.context.stroke()
      })
    }
    .width('100%')
    .height('100%')
  }
}

1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.