Tabs组件如何实现TabBar不均分，居左，居中或居右显示的效果？

@Entry  
@Component  
struct TabDemo5 {  
  @State tabArray: Array<number> = [0, 1]  
  @State focusIndex: number = 0  
  @State pre: number = 0  
  @State index: number = 0  
  private controller: TabsController = new TabsController()  
  @State test: boolean = false  
  // 单独的页签  
  @Builder  
  Tab(tabName: string, tabItem: number, tabIndex: number) {  
    Column({ space: 20 }) {  
      Text(tabName).fontSize(18)  
      Image($r('app.media.icon')).width(20).height(20)  
    }  
    .width(100)  
    .height(60)  
    .borderRadius({ topLeft: 10, topRight: 10 })  
    .onClick(() => {  
      this.controller.changeIndex(tabIndex)  
      this.focusIndex = tabIndex  
    })  
    .backgroundColor(tabIndex === this.focusIndex ? "#ffffffff" : "#ffb7b7b7")  
  }  
  build() {  
    Column() {  
      Column() {  
        // 页签  
        Row({ space: 7 }) {  
          Scroll() {  
            Row() {  
              ForEach(this.tabArray, (item: number, index: number) => {  
                this.Tab("页" + item, item, index)  
              })  
            }  
            .justifyContent(FlexAlign.Start)  
          }  
          .align(Alignment.Start)  
          .scrollable(ScrollDirection.Horizontal)  
          .scrollBar(BarState.Off)  
          .width('80%')  
          .backgroundColor("#ffb7b7b7")  
        }  
        .width('100%')  
        .backgroundColor("#ffb7b7b7")  
        //tabs  
        Tabs({ barPosition: BarPosition.Start, controller: this.controller }) {  
          ForEach(this.tabArray, (item: number, index: number) => {  
            TabContent() {  
              Text('我是页面 ' + item + " 的内容")  
                .height(300)  
                .width('100%')  
                .fontSize(30)  
            }  
            .backgroundColor(Color.Blue)  
          })  
        }  
        .barHeight(0)  
        .animationDuration(100)  
        .onChange((index: number) => {  
          console.log('foo change')  
          this.focusIndex = index  
        })  
      }  
      .alignItems(HorizontalAlign.Start)  
      .width('100%')  
    }  
    .height('100%')  
  }  
}