HarmonyOS Swiper组件的Indicator设置bottom（0）没有贴底

class MyDataSource implements IDataSource { 
 private list: number[] = [] 
 constructor(list: number[]) { 
  this.list = list 
 } 
 totalCount(): number { 
  return this.list.length 
 } 
 getData(index: number): number { 
  return this.list[index] 
 } 
 registerDataChangeListener(listener: DataChangeListener): void {} 
 unregisterDataChangeListener() {} 
} 
 
@Entry 
@Component 
struct SwiperExample { 
 private swiperController: SwiperController = new SwiperController() 
 private data: MyDataSource = new MyDataSource([]) 
 @State widthLength:number=0 
 @State heightLength:number=0 
 @State currentIndex:number=0 
 
 // 实现导航点自定义动画 
 private swiperWidth: number = 0 
 private getTextInfo(index: number): Record<string, number> { 
  let strJson = getInspectorByKey(index.toString()) 
  try { 
   let obj: Record<string, string> = JSON.parse(strJson) 
   let rectInfo: number[][] = JSON.parse('[' + obj.$rect + ']') 
   return { 'left': px2vp(rectInfo[0][0]), 'width': px2vp(rectInfo[1][0] - rectInfo[0][0]) } 
  } catch (error) { 
   return { 'left': 0, 'width': 0 } 
  } 
 } 
 
 private getCurrentIndicatorInfo(index: number, event: TabsAnimationEvent): Record<string, number> { 
  let nextIndex = index 
  if (index > 0 && event.currentOffset > 0) { 
   nextIndex-- 
  } else if (index < 3 && event.currentOffset < 0) { 
   nextIndex++ 
  } 
  let indexInfo = this.getTextInfo(index) 
  let nextIndexInfo = this.getTextInfo(nextIndex) 
  let swipeRatio = Math.abs(event.currentOffset / this.swiperWidth) 
  let currentIndex = swipeRatio > 0.5 ? nextIndex : index // 页面滑动超过一半，swiper切换到下一页。 
  let currentLeft = indexInfo.left + (nextIndexInfo.left - indexInfo.left) * swipeRatio 
  let currentWidth = indexInfo.width + (nextIndexInfo.width - indexInfo.width) * swipeRatio 
  return { 'index': currentIndex, 'left': currentLeft, 'width': currentWidth } 
 } 
 
 aboutToAppear(): void { 
  let list: number[] = [] 
  for (let i = 1; i <= 4; i++) { 
   list.push(i); 
  } 
  this.data = new MyDataSource(list) 
 } 
 
 build() { 
  Column({ space: 5 }) { 
   Stack({ alignContent: Alignment.Bottom }) { 
    Swiper(this.swiperController) { 
     LazyForEach(this.data, (item: string) => { 
      Text(item.toString()) 
       .width('90%') 
       .height(160) 
       .backgroundColor(0xAFEEEE) 
       .textAlign(TextAlign.Center) 
       .fontSize(30) 
     }, (item: string) => item) 
    } 
    .cachedCount(2) 
    .index(0) 
    .autoPlay(false) 
    .interval(4000) 
    .loop(true) 
    .duration(1000) 
    .itemSpace(0) 
    .indicator(false) 
    .curve(Curve.Linear) 
    .onChange((index: number) => { 
     console.info(index.toString()) 
     this.currentIndex=index 
    }) 
    .onGestureSwipe((index: number, extraInfo: SwiperAnimationEvent) => { 
     // 在页面跟手滑动过程中，逐帧触发该回调。 
     let currentIndicatorInfo = this.getCurrentIndicatorInfo(index,extraInfo) 
     this.currentIndex = currentIndicatorInfo.index 
    }) 
    .onAnimationStart((index: number, targetIndex: number, extraInfo: SwiperAnimationEvent) => { 
     // 切换动画开始时触发该回调。下划线跟着页面一起滑动，同时宽度渐变。 
     this.currentIndex = targetIndex 
    }) 
    .onAnimationEnd((index: number, extraInfo: SwiperAnimationEvent) => { 
     console.info("current offset: " + extraInfo.currentOffset) 
    }) 
    Row() { 
     LazyForEach(this.data, (item: string, index: number) => { 
      Column() 
       .width(55) 
       .height(5) 
       .margin(2) 
       .borderRadius(5) 
       .backgroundColor(this.currentIndex===index?Color.Red:Color.Gray) 
     }, (item: string) => item) 
    } 
    .position({x:0,y:150}) 
   } 
  }.width('100%') 
  .margin({ top: 5 }) 
 } 
}