HarmonyOS List组件的scroller.scrollToIndex()在某些场景不起作用

class DataSource implements IDataSource {  
  private listeners: DataChangeListener[] = [];  
  
  registerDataChangeListener(listener: DataChangeListener): void {  
    if (this.listeners.indexOf(listener) < 0) {  
      this.listeners.push(listener);  
    }  
  }  
  unregisterDataChangeListener(listener: DataChangeListener): void {  
    let pos = this.listeners.indexOf(listener);  
    if (pos >= 0) {  
      this.listeners.splice(pos, 1);  
    }  
  }  
  
  data:string[] = Array(20000).fill("0");  
  getData(index: number): string {  
    return index + ""  
  }  
  
  totalCount(): number {  
    return 20000  
  }  
}  
@Entry  
@Component  
export struct TestCompPage {  
  // scroller:Scroller = new Scroller();  
  scroller: ListScroller = new ListScroller()  
  dataSource = new DataSource();  
  
  @Builder BuildFooter(){  
    Text("触底啦...").width("100%");  
  }  
  
  build() {  
    Column(){  
      Button("scrollTo 80").onClick(() => {  
        this.scroller.scrollToItemInGroup(0,80);  
      })  
  
      List({scroller:this.scroller}){  
        ListItemGroup({footer:this.BuildFooter()}){  
          LazyForEach(this.dataSource,(item:string,index:number) => {  
            ListItem(){  
              Text(index + "").height(20)  
            }  
          })  
        }  
  
      }.cachedCount(2)  
    }  
  }  
}