HarmonyOS Refresh组件，在刷新组件时如何设置高度？

@Entry  
@Component  
struct RefreshNestScroll {  
  private arr: number[] = [0, 1, 2, 3]  
  @State isRefreshing: boolean = false  
  scroller: Scroller = new Scroller()  
  build() {  
    Column() {  
      Refresh({ refreshing: $$this.isRefreshing }) {  
        Scroll() {  
          Column() {  
            Text('我是scroll顶端').height(100)  
            List() {  
              ForEach(this.arr, (item: number) => {  
                ListItem() {  
                  Text('' + item)  
                }.height(100).width('100%')  
              })  
            }  
            .divider({ strokeWidth: 0.5, color: Color.Red })  
            .width('100%')  
            .height('100%')  
            .backgroundColor('#FFDDFF')  
            .nestedScroll({  
              scrollForward: NestedScrollMode.PARENT_FIRST,  
              scrollBackward: NestedScrollMode.SELF_FIRST  
            })  
            Text('我是scroll底端').height(100)  
          }  
        }.width('100%').height('100%').backgroundColor(Color.Gray)  
        .nestedScroll({  
          scrollForward: NestedScrollMode.PARENT_FIRST,  
          scrollBackward: NestedScrollMode.SELF_FIRST  
        })  
      }  
      .onRefreshing(() => {  
        setTimeout(() => {  
          this.isRefreshing = !this.isRefreshing  
        }, 2000)  
      })  
    }.width('100%').height(400).backgroundColor(0xDCDCDC).justifyContent(FlexAlign.Center)  
  }  
}