如何通过代码触发滚动条滚动到某个位置

@Entry 
@Component 
struct ListExample { 
  private arr: number[] = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] 
  listScroller: ListScroller = new ListScroller() 
  build() { 
    Column() { 
      Button('跳转至头部') 
        .onClick(()=>{ 
          this.listScroller.scrollTo({ xOffset: 0, yOffset: 0 }) 
        }) 
      List({ space: 20, initialIndex: 0 ,scroller :this.listScroller }) { 
        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(EdgeEffect.Spring) // 边缘效果设置为Spring 
      .onScrollIndex((firstIndex: number, lastIndex: number, centerIndex: number) => { 
        console.info('first' + firstIndex) 
        console.info('last' + lastIndex) 
        console.info('center' + centerIndex) 
      }) 
      .onScroll((scrollOffset: number, scrollState: ScrollState) => { 
        console.info(`onScroll scrollState = ScrollState` + scrollState + `, scrollOffset = ` + scrollOffset) 
      }) 
      .width('90%') 
    } 
    .width('100%') 
    .height('100%') 
    .backgroundColor(0xDCDCDC) 
    .padding({ top: 5 }) 
  } 
}
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