HarmonyOS border的width属性小于0.3就不显示，现在需要width：0.15请问怎么解决

@Entry 
@Component 
struct BorderExample3 { 
  @State textWidth: Length = 0; 
  @State textHeight: Length = 0; 
  private textBorderWidth: number = 0.15 
  build() { 
    RelativeContainer() { 
      // 背景 
      Text('') 
        .width(this.textBorderWidth * 2 + (this.textWidth as number)) 
        .height(this.textBorderWidth * 2 + (this.textHeight as number)) 
        .backgroundColor(Color.Black) 
        .alignRules({ 
          top: { anchor: '__container__', align: VerticalAlign.Top }, 
          left: { anchor: '__container__', align: HorizontalAlign.Start } 
        }) 
        .id("back1") 
 
      // 文本 
      Text('一二三一二三一二三一二三一二三一二三一二三一二三') 
        .fontSize(30) 
        .onAreaChange((oldValue: Area, newValue: Area) => { 
          this.textWidth = newValue.width 
          this.textHeight = newValue.height 
        }) 
        .margin({ top: this.textBorderWidth, left: this.textBorderWidth }) 
        .width(200) 
        .backgroundColor(Color.White) 
        .alignRules({ 
          top: { anchor: "back1", align: VerticalAlign.Top }, 
          left: { anchor: "back1", align: HorizontalAlign.Start }, 
        }) 
        .id("text1") 
    } 
    .width('100%').height('100%') 
    .margin({ left: 50 }) 
  } 
}