HarmonyOS 鸿蒙Next DigitIndicator的背景怎么设置

参考：Swiper-滚动与滑动-ArkTS组件-ArkUI（方舟UI框架）-应用框架 - 华为HarmonyOS开发者

可以自定义下indicator来实现这个效果，demo 如下：

// xxx.ets
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 {
  @State curIndex: number = 1;
  private swiperController: SwiperController = new SwiperController()
  private data: MyDataSource = new MyDataSource([])

  aboutToAppear(): void {
    let list: number[] = []
    for (let i = 1; i <= 10; i++) {
      list.push(i);
    }
    this.data = new MyDataSource(list)
  }
  build() {
    Column({ space: 5 }) {
      Stack() {
        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)
        .autoPlay(true)
        .interval(4000)
        .indicator(false)
        .loop(true)
        .duration(1000)
        .itemSpace(0)
        .displayArrow(true, false)
        .onChange((index: number) => {
          this.curIndex = index+1;
        })

        Row() {
          Text(this.curIndex + '').fontSize(20)
          Text('/')
          Text(this.data.totalCount() + '')
        }
        .backgroundColor('#bb999999')
        .padding({
          top: 2,
          right: 8,
          bottom: 2,
          left: 8
        })
        .borderRadius(8)
        .offset({ x: 120, y: 60 })
      }

      Row({ space: 12 }) {
        Button('showNext')
          .onClick(() => {
            this.swiperController.showNext()
          })
        Button('showPrevious')
          .onClick(() => {
            this.swiperController.showPrevious()
          })
      }.margin(5)
    }
    .width('100%')
    .margin({ top: 5 })
  }
}