HarmonyOS 关于Tabs、TabContent组件滑动联动问题的咨询

enum ScrollPosition { 
 start, 
 center, 
 end 
} 
 
class ItemClass { 
 content: string = ''; 
 color: Color = Color.White; 
} 
 
@Entry 
@Component 
struct NestedScrollDemo { 
 @State listPosition: number = ScrollPosition.start; // 0代表滚动到List顶部，1代表中间值，2代表滚动到List底部。 
 @State scrollPosition: number = ScrollPosition.start; // 0代表滚动到页面顶部，1代表中间值，2代表滚动到页面底部。 
 @State showTitle: boolean = false; 
 @State currentYOffset: number = 0; 
 private arr: ItemClass[] = []; 
 private colorArr: Color[] = [Color.White, Color.Blue, Color.Brown, Color.Green, Color.Gray]; 
 private scrollerForScroll: Scroller = new Scroller(); 
 private scrollerForList: Scroller = new Scroller(); 
 private scrollerForTitle: Scroller = new Scroller(); 
 @State currentIndex: number = 0; 
 
 aboutToAppear() { 
  for (let i = 0; i < 6; i++) { 
   let data: ItemClass = { 
    content: i.toString(), 
    color: this.colorArr[i % 5] 
   } 
   this.arr.push(data); 
  } 
 } 
 
 @Builder 
 myBuilder() { 
  Row() { 
   List({ space: 2, initialIndex: 0, scroller: this.scrollerForTitle }) { 
    ForEach(this.arr, (item: ItemClass, index) => { 
     ListItem() { 
      Column() { 
       Text(item.content); 
       Divider() 
        .color('#000000') 
        .strokeWidth(5) 
        .visibility(index == this.currentIndex ? Visibility.Visible : Visibility.Hidden) 
      } 
      .width('25%') 
      .height(50) 
      .onClick(() => { 
       this.scrollerForList.scrollToIndex(index) 
       this.scrollerForScroll.scrollEdge(Edge.Bottom) 
      }) 
     } 
    }) 
   } 
   .listDirection(Axis.Horizontal) 
   .scrollBar(BarState.Off) 
  } 
  .backgroundColor('#ffe2d0d0') 
  .alignItems(VerticalAlign.Center) 
 } 
 
 build() { 
  Stack({ alignContent: Alignment.Top }) { 
   Scroll(this.scrollerForScroll) { 
    Column() { 
     Image($r('app.media.app_icon')) 
      .width("100%") 
      .height("40%") 
     this.myBuilder(); 
 
     List({ space: 10, scroller: this.scrollerForList }) { 
      ForEach(this.arr, (item: ItemClass, index) => { 
       ListItem() { 
        Column() { 
         Text(item.content) 
         //添加其他内容 
        } 
        .width('100%') 
        .height(500) 
        .backgroundColor(item.color) 
       }.width("100%").height(500) 
       .onVisibleAreaChange([0.8], (isVisible) => { 
        if (isVisible) { 
         this.currentIndex = index; 
         this.scrollerForTitle.scrollToIndex(this.currentIndex); 
        } 
       }) 
      }, (item: ItemClass) => item.content) 
     } 
     .padding({ left: 10, right: 10 }) 
     .width("100%") 
     .edgeEffect(EdgeEffect.None) 
     .scrollBar(BarState.Off) 
     .onReachStart(() => { 
      this.listPosition = ScrollPosition.start 
     }) 
     .onReachEnd(() => { 
      this.listPosition = ScrollPosition.end 
     }) 
     .onScrollFrameBegin((offset: number, state: ScrollState) => { 
      // 滑动到列表中间时 
      if (!((this.listPosition == ScrollPosition.start && offset < 0) 
       || (this.listPosition == ScrollPosition.end && offset > 0))) { 
       this.listPosition = ScrollPosition.center 
      } 
 
      // 如果页面已滚动到底部，列表不在顶部或列表有正向偏移量 
      if (this.scrollPosition == ScrollPosition.end 
       && (this.listPosition != ScrollPosition.start || offset > 0)) { 
       return { offsetRemain: offset }; 
      } else { 
       this.scrollerForScroll.scrollBy(0, offset) 
       return { offsetRemain: 0 }; 
      } 
     }) 
     .width("100%") 
     .height("calc(100% - 50vp)") 
     .backgroundColor('#F1F3F5') 
    } 
   } 
   .scrollBar(BarState.Off) 
   .width("100%") 
   .height("100%") 
   .onScroll((xOffset: number, yOffset: number) => { 
    this.currentYOffset = this.scrollerForScroll.currentOffset().yOffset; 
 
    // 非（页面在顶部或页面在底部），则页面在中间 
    if (!((this.scrollPosition == ScrollPosition.start && yOffset < 0) 
     || (this.scrollPosition == ScrollPosition.end && yOffset > 0))) { 
     this.scrollPosition = ScrollPosition.center 
    } 
   }) 
   .onScrollEdge((side: Edge) => { 
    if (side == Edge.Top) { 
     // 页面在顶部 
     this.scrollPosition = ScrollPosition.start 
    } else if (side == Edge.Bottom) { 
     // 页面在底部 
     this.scrollPosition = ScrollPosition.end 
    } 
   }) 
   .onScrollFrameBegin(offset => { 
    if (this.scrollPosition == ScrollPosition.end) { 
     return { offsetRemain: 0 }; 
    } else { 
     return { offsetRemain: offset }; 
    } 
   }) 
  } 
  .width('100%') 
  .height('100%') 
  .backgroundColor(0xDCDCDC) 
 } 
}