HarmonyOS 嵌套滚动冲突？

Question

Scroll-\>Tabs-\>List嵌套时，给List添加nestedScroll无法解决滚动冲突

Scroll包含Tabs，Tabs中的TabContent包含List，此时给List增加：

.nestedScroll({
  scrollForward: NestedScrollMode.PARENT_FIRST,
  scrollBackward: NestedScrollMode.SELF_FIRST
})

期望Scroll和List同时只有一个滚动，但是现在是两个都可以响应滚动。

Answer 1

请参考demo

@Entry
@Component
struct page240429110107050 {
  @State message: string = 'Hello World'
  @State arr: number[] = []
  private touchDown: boolean = false;
  private listTouchDown: boolean = false;
  private scrolling: boolean = false;
  private scroller: Scroller = new Scroller()
  private listScroller: Scroller = new Scroller()

  @Styles
  listCard() {
    .backgroundColor(Color.White)
    .height(72)
    .width("100%")
    .borderRadius(12)
  }

  build() {
    Scroll(this.scroller) {
      Column() {
        Text("Scroll Area")
          .width("100%")
          .height("400")
          .backgroundColor('#0080DC')
          .textAlign(TextAlign.Center)
        Tabs({ barPosition: BarPosition.Start }) {
          TabContent() {
            List({ space: 10, scroller: this.listScroller }) {
              ForEach(this.arr, (item: number) => {
                ListItem() {
                  Text("item" + item)
                    .fontSize(16)
                }.listCard()
              }, (item: number) => item.toString())
            }.width("100%")
            .edgeEffect(EdgeEffect.Spring)
            .nestedScroll({
              scrollForward: NestedScrollMode.PARENT_FIRST,
              scrollBackward: NestedScrollMode.SELF_FIRST
            })
            .onTouch((event: TouchEvent) => {
              if (event.type == TouchType.Down) {
                this.listTouchDown = true;
              } else if (event.type == TouchType.Up) {
                this.listTouchDown = false;
              }
            })
          }.tabBar("Tab1")

          TabContent() {
          }.tabBar("Tab2")
        }
        .vertical(false)
        .height("100%")

        // .height(300)

        // Column()
        // .width('100%')
        // .height(1000)
      }.width("100%")
    }
    .onTouch((event: TouchEvent) => {
      if (event.type == TouchType.Down) {
        this.touchDown = true;
      } else if (event.type == TouchType.Up) {
        this.touchDown = false;
      }
    })
    .onScrollFrameBegin((offset: number, state: ScrollState) => {
      if (this.scrolling && offset > 0) {
        let yOffset: number = this.scroller.currentOffset().yOffset
        if (yOffset >= 400) {
          this.listScroller.scrollBy(0, offset)
          return { offsetRemain: 0 }
        } else if (yOffset + offset > 400) {
          this.listScroller.scrollBy(0, yOffset + offset - 400)
          return { offsetRemain: 400 - yOffset }
        }
      }
      return { offsetRemain: offset }
    })
    .onScrollStart(() => {
      if (this.touchDown && !this.listTouchDown) {
        this.scrolling = true;
      }
    })
    .onScrollStop(() => {
      this.scrolling = false;
    })
    .edgeEffect(EdgeEffect.Spring)
    .backgroundColor('#DCDCDC')
    .scrollBar(BarState.Off)
    .width('100%')
    .height('100%')
  }

  aboutToAppear() {
    for (let i = 0; i < 30; i++) {
      this.arr.push(i)
    }
  }
}