HarmonyOS鸿蒙Next中List组件滚动到顶部，追加数据，保持滚动条不动的问题

开发者您好，我这边根据您的问题描述采用做了一下验证，将List滚动到顶部，在顶部追加数据，使用 this.scroller.scrollToIndex(currentIndex); 是可以保持滚动条不变维持当前显示数据的。

Text组件或者封装的Component都是正常的。您这边如果出现了scroller跳转不准确，导致可见内容下移的为每桶，是否方便提供一个完整Demo便于我们这边分析定位问题。

以下是我这边的验证代码，您可以看下是否是您需要的场景：

// ListDataSource.ets
export class ListDataSource implements IDataSource {
  private list: number[] = [];
  private listeners: DataChangeListener[] = [];

  constructor(list: number[]) {
    this.list = list;
  }

  totalCount(): number {
    return this.list.length;
  }

  getData(index: number): number {
    return this.list[index];
  }

  registerDataChangeListener(listener: DataChangeListener): void {
    if (this.listeners.indexOf(listener) < 0) {
      this.listeners.push(listener);
    }
  }

  unregisterDataChangeListener(listener: DataChangeListener): void {
    const pos = this.listeners.indexOf(listener);
    if (pos >= 0) {
      this.listeners.splice(pos, 1);
    }
  }

  // 通知LazyForEach组件需要重载所有子组件
  notifyDataReload(): void {
    this.listeners.forEach(listener => {
      listener.onDataReloaded();
    });
  }

  // 通知控制器数据删除
  notifyDataDelete(index: number): void {
    this.listeners.forEach(listener => {
      listener.onDataDelete(index);
    });
  }

  // 通知控制器添加数据
  notifyDataAdd(index: number): void {
    this.listeners.forEach(listener => {
      listener.onDataAdd(index);
    });
  }

  // 在指定索引位置删除一个元素
  public deleteItem(index: number): void {
    this.list.splice(index, 1);
    this.notifyDataDelete(index);
  }

  // 在指定索引位置插入一个元素
  public insertItem(index: number, data: number): void {
    this.list.splice(index, 0, data);
    console.log(JSON.stringify(this.list));
    this.notifyDataAdd(index);
  }

  public reloadData(): void {
    this.notifyDataReload();
  }
}

@Component
struct ItemList {
  @Prop item:number;
  build() {
    Text('ItemList+' + this.item)
      .width('100%')
      .height(100)
      .fontSize(16)
      .textAlign(TextAlign.Center)
      .borderRadius(10)
      .backgroundColor(0xFFFFFF)
  }
}

@Entry
@Component
struct ListExample {
  private arr: ListDataSource =
    new ListDataSource([0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19]);
  @State currentIndex: number = 0;
  private scroller: ListScroller = new ListScroller();
  build() {
    Column() {
      List({ space: 20, initialIndex: 0, scroller: this.scroller }) {
        LazyForEach(this.arr, (item: number) => {
          ListItem() {
            ItemList({item: item})
          }
        }, (item: number) => item.toString())
      }
      .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);
        this.currentIndex = firstIndex;
      })
      .onScrollVisibleContentChange((start: VisibleListContentInfo, end: VisibleListContentInfo) => {
        console.info(' start index: ' + start.index +
          ' start item group area: ' + start.itemGroupArea +
          ' start index in group: ' + start.itemIndexInGroup);
        console.info(' end index: ' + end.index +
          ' end item group area: ' + end.itemGroupArea +
          ' end index in group: ' + end.itemIndexInGroup);
      })
      .onDidScroll((scrollOffset: number, scrollState: ScrollState) => {
        console.info(`onScroll scrollState = ScrollState` + scrollState + `, scrollOffset = ` + scrollOffset);
      })
      .width('90%')
      .height('90%')

      Button('顶部新增3条').onClick(() => {
        const newArr = [-1, -2, -3];
        newArr.forEach((item: number) => {
          this.arr.insertItem(0, item);
        })
        this.currentIndex = this.currentIndex + newArr.length;
        // this.scroller.scrollToIndex(this.currentIndex)
      })
    }
    .width('100%')
    .height('100%')
    .backgroundColor(0xDCDCDC)
    .padding({ top: 5 })
  }
}