HarmonyOS UI布局水平居中问题

format= 's' 不会补0，代码如下:

@Component
export struct MyTextTimer {
  textTimerController: TextTimerController = new TextTimerController();
  @Prop format: string;
  aboutToAppear(): void {
    this.textTimerController.start();
  }

  build() {
    Column() {
      TextTimer({ isCountDown: true, count: 30000, controller: this.textTimerController })
        .format(this.format)
        .fontColor(Color.Black)
        .fontSize(50)
        .onTimer((utc: number, elapsedTime: number) => {
          console.info('textTimer notCountDown utc is：' + utc + ', elapsedTime: ' + elapsedTime)
        })
      Row() {
        Button('start').onClick(() => {
          this.textTimerController.start()
        })
        Button('pause').onClick(() => {
          this.textTimerController.pause()
        })
        Button('reset').onClick(() => {
          this.textTimerController.reset()
        })
      }
    }
  }
}

@Entry
@Component
struct Index {

  @State format: string = 's'
  onPageShow(): void {
  }
  build() {
    Column() {
      MyTextTimer({format:this.format})
    }
  }
}

自适应拉伸 flexBasis('auto')

https://developer.huawei.com/consumer/cn/doc/harmonyos-guides-V5/arkts-layout-development-flex-layout-V5