滑动选择组件，有谁知道怎么解决吗?

 Row() { 
  
          ForEach(this.text_list1, (value: string,idx:number) => { 
            Text(value) 
              .width(this.childWidth) 
              .height(this.childHeight) 
              .fontSize(20) 
              .backgroundColor(this.color_list1[Math.floor(8*Math.random())]) 
              .textAlign(TextAlign.Center) 
          }) 
        } 
        .height(this.childHeight) 
        .width(this.childWidth*this.text_list1.length)

 .onTouch((event: TouchEvent) => { 
          if (event.type === TouchType.Down) { 
            if (this.isOnTouchInParent(event)) { 
              this.displayMsg = '#<' 
              this.textTemp = this.getChildText(event) 
              this.displayMsg = this.displayMsg + this.textTemp 
            } 
          } 
          if (event.type === TouchType.Up) { 
            if (this.isOnTouchInParent(event)) { 
              this.displayMsg = this.displayMsg + '>' 
              this.textTemp = '' 
            } 
  
          } 
          if (event.type === TouchType.Move) { 
            if (this.isOnTouchInParent(event)) { 
              if (this.textTemp === this.getChildText(event)) { 
  
              }else { 
                this.textTemp = this.getChildText(event) 
                this.displayMsg = this.displayMsg + this.textTemp 
              } 
  
            } 
          } 
        })

isOnTouchInParent(event: TouchEvent) :boolean{ 
    if (event.touches[0].x>0 &&event.touches[0].x<=this.childWidth*this.text_list1.length && event.touches[0].y>0&&event.touches[0].y<this.childWidth) { 
      return true; 
    } 
    return false 
  } 
  getChildText(event: TouchEvent) :string{ 
    return this.text_list1[Math.floor(event.touches[0].x/this.childWidth)] 
  }