List组件如何设置两端的渐变效果

@Entry 
@Component 
struct ListExample { 
  @State arr: number[] = [1, 2, 3, 4, 5, 6, 7, 8, 9] 
  private scroller: Scroller = new Scroller() 
 
  build() { 
    Stack() { 
      List({ space: 10 }) { 
        ForEach(this.arr, (item: string) => { 
          ListItem() { 
            Text("中国潮色") 
              .width(100) 
              .height(64) 
              .fontColor(Color.White) 
              .backgroundColor(Color.Black) 
              .textAlign(TextAlign.Center) 
          } 
        }, (item: string) => item) 
      } 
      .listDirection(Axis.Horizontal) 
      .scrollBar(BarState.Off) 
      .padding({ top: 20, bottom: 20 }) 
      .width("80%") 
      .height("100%") 
 
      Stack() { 
 
      } 
      .linearGradient({ 
        angle: 90, 
        colors: [[0x000000, 0.0], ['rgba(0,0,0,0)', 0.1], ['rgba(0,0,0,0)', 0.9], [0x000000, 1.0]] 
      }) 
      .width("80%") 
      .height("100%") 
      .hitTestBehavior(HitTestMode.None) 
    }.height(100).width('100%').backgroundColor(Color.Black) 
  } 
}