HarmonyOS ListItem如何获取在List中的偏移量

参考demo：

// xxx.ets
@Entry
@Component
struct ListExample {
  private arr: number[] = []
  private scrollerForList: Scroller = new Scroller()

  aboutToAppear() {
    for (let i = 0; i < 20; i++) {
      this.arr.push(i)
    }
  }
  build() {
    Column() {
      Row() {
        List({ space: 20, initialIndex: 3, scroller: this.scrollerForList }) {
          ForEach(this.arr, (item: number) => {
            ListItem() {
              Text('' + item)
                .width('100%').height(100).fontSize(16)
                .textAlign(TextAlign.Center)
            }
            .borderRadius(10).backgroundColor(0xFFFFFF)
            .width('60%')
            .height('80%')
          }, (item: number) => JSON.stringify(item))
        }
        .onScroll(()=>{
          console.log(this.scrollerForList.currentOffset().xOffset+' this.scrollerForList.currentOffset().xOffset')
        })
        .chainAnimation(true)
        .edgeEffect(EdgeEffect.Spring)
        .listDirection(Axis.Horizontal)
        .height('100%')
        .width('100%')
        .scrollSnapAlign(ScrollSnapAlign.CENTER)
        .borderRadius(10)
        .backgroundColor(0xDCDCDC)
      }
      .width('100%')
      .height('100%')
      .backgroundColor(0xDCDCDC)
      .padding({ top: 10 })
    }
  }
}