HarmonyOS API：容器组件

scroller: Scroller = new Scroller()

// xxx.ets
@Entry
@Component
struct ScrollExample {
  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) => {
            Text(item.toString())
              .width('90%')
              .height(150)
              .backgroundColor(0xFFFFFF)
              .borderRadius(15)
              .fontSize(16)
              .textAlign(TextAlign.Center)
              .margin({ top: 10 })
          }, item => 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(30) // 滚动条宽度
      .edgeEffect(EdgeEffect.None)
      .onScroll((xOffset: number, yOffset: number) => {
        console.info(xOffset + ' ' + yOffset)
      })
      .onScrollEdge((side: Edge) => {
        console.info('To the edge')
      })
      .onScrollEnd(() => {
        console.info('Scroll Stop')
      })

      Button('scroll 150')
        .onClick(() => { // 点击后下滑指定距离150.0vp
          this.scroller.scrollBy(0,150)
        })
        .margin({ top: 10, left: 20 })
      Button('scroll 100')
        .onClick(() => { // 点击后滑动到指定位置，即下滑100.0vp的距离
          this.scroller.scrollTo({ xOffset: 0, yOffset: this.scroller.currentOffset().yOffset + 100 })
        })
        .margin({ top: 60, left: 20 })
      Button('back top')
        .onClick(() => { // 点击后回到顶部
          this.scroller.scrollEdge(Edge.Top)
        })
        .margin({ top: 110, left: 20 })
      Button('next page')
        .onClick(() => { // 点击后滑到下一页
          this.scroller.scrollPage({ next: true })
        })
        .margin({ top: 170, left: 20 })
    }.width('100%').height('100%').backgroundColor(0xDCDCDC)
  }
}

@Entry
@Component
struct NestedScroll {
  @State listPosition: number = 0; // 0代表滚动到List顶部，1代表中间值，2代表滚动到List底部。
  private arr: number[] = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
  private scrollerForScroll: Scroller = new Scroller()
  private scrollerForList: Scroller = new Scroller()

  build() {
    Flex() {
      Scroll(this.scrollerForScroll) {
        Column() {
          Text("Scroll Area")
            .width("100%").height("40%").backgroundColor(0X330000FF)
            .fontSize(16).textAlign(TextAlign.Center)
            .onClick(() => {
              this.scrollerForList.scrollToIndex(5)
            })

          List({ space: 20, scroller: this.scrollerForList }) {
            ForEach(this.arr, (item) => {
              ListItem() {
                Text("ListItem" + item)
                  .width("100%").height("100%").borderRadius(15)
                  .fontSize(16).textAlign(TextAlign.Center).backgroundColor(Color.White)
              }.width("100%").height(100)
            }, item => item)
          }
          .width("100%")
          .height("50%")
          .edgeEffect(EdgeEffect.None)
          .onReachStart(() => {
            this.listPosition = 0
          })
          .onReachEnd(() => {
            this.listPosition = 2
          })
          .onScrollBegin((dx: number, dy: number) => {
            if ((this.listPosition == 0 && dy >= 0) || (this.listPosition == 2 && dy <= 0)) {
              this.scrollerForScroll.scrollBy(0, -dy)
              return { dxRemain: dx, dyRemain: 0 }
            }
            this.listPosition = 1
            return { dxRemain: dx, dyRemain: dy };
          })

          Text("Scroll Area")
            .width("100%").height("40%").backgroundColor(0X330000FF)
            .fontSize(16).textAlign(TextAlign.Center)
        }
      }
      .width("100%").height("100%")
    }.width('100%').height('100%').backgroundColor(0xDCDCDC).padding(20)
  }
}

// xxx.ets
@Entry
@Component
struct StackExample {
  build() {
    Stack({ alignContent: Alignment.Bottom }) {
      Text('First child, show in bottom').width('90%').height('100%').backgroundColor(0xd2cab3).align(Alignment.Top)
      Text('Second child, show in top').width('70%').height('60%').backgroundColor(0xc1cbac).align(Alignment.Top)
    }.width('100%').height(150).margin({ top: 5 })
  }
}