如何实现scroll、list单边回弹效果

@Entry 
@Component 
struct Index { 
  @State yOffset: number = 0 
  scroller: Scroller = new Scroller() 
  private arr: number[] = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] 
 
  build() { 
    Stack({ alignContent: Alignment.TopStart }) { 
      Scroll(this.scroller) { 
        Column() { 
          ForEach(this.arr, (item: number) => { 
            Text(item.toString()) 
              .width('90%') 
              .height(150) 
              .backgroundColor(0xFFFFFF) 
              .borderRadius(15) 
              .fontSize(16) 
              .textAlign(TextAlign.Center) 
              .margin({ top: 10 }) 
          }, (item: string) => item) 
        }.width('100%') 
      } 
      .scrollable(ScrollDirection.Vertical) // 滚动方向纵向 
      .scrollBar(BarState.On) // 滚动条常驻显示 
      .scrollBarColor(Color.Gray) // 滚动条颜色 
      .scrollBarWidth(10) // 滚动条宽度 
      .friction(0.6) 
      .edgeEffect(this.yOffset <= 0 ? EdgeEffect.Spring : EdgeEffect.None) // 滚动到边沿后回弹 
      .onDidScroll(() => { 
        this.yOffset = this.scroller.currentOffset().yOffset; 
      }) 
    }.width('100%').height('100%').backgroundColor(0xDCDCDC) 
  } 
}
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@Entry 
@Component 
struct Index { 
  private arr: number[] = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] 
  @State isTop: boolean = true 
  build() { 
    Column() { 
      List({ space: 20, initialIndex: 0 }) { 
        ForEach(this.arr, (item: number) => { 
          ListItem() { 
            Text('' + item) 
              .width('100%') 
              .height(100) 
              .fontSize(16) 
              .textAlign(TextAlign.Center) 
              .borderRadius(10) 
              .backgroundColor(0xFFFFFF) 
          } 
        }, (item: string) => item) 
      } 
      .listDirection(Axis.Vertical) // 排列方向 
      .scrollBar(BarState.Off) 
      .friction(0.6) 
      .divider({ strokeWidth: 2, color: 0xFFFFFF, startMargin: 20, endMargin: 20 }) // 每行之间的分界线 
      .edgeEffect(this.isTop ? EdgeEffect.None : EdgeEffect.Spring) 
      .onScrollIndex((firstIndex: number, lastIndex: number, centerIndex: number) => { 
        if (firstIndex === 0) { 
          this.isTop = true 
        } else { 
          this.isTop = false 
        } 
      }) 
      .width('90%') 
    } 
    .width('100%') 
    .height('100%') 
    .backgroundColor(0xDCDCDC) 
    .padding({ top: 5 }) 
  } 
}
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