HarmonyOS 怎么修改半模态转场页面顶部圆角大小

@Entry 
@Component 
struct Index { 
  @State isShow:boolean = false 
  @State isShow2:boolean = false 
  @State sheetHeight:number = 300; 
 
  @Builder myBuilder() { 
    Column() { 
      Button("change height") 
        .margin(10) 
        .fontSize(20) 
        .onClick(()=>{ 
          this.sheetHeight = 500; 
        }) 
 
      Button("Set Illegal height") 
        .margin(10) 
        .fontSize(20) 
        .onClick(()=>{ 
          this.sheetHeight = -1; 
        }) 
 
      Button("close modal 1") 
        .margin(10) 
        .fontSize(20) 
        .onClick(()=>{ 
          this.isShow = false; 
        }) 
    } 
    .width('100%') 
    .height('100%') 
    //border颜色和backgroundColor一致 
    .backgroundColor("#36D") 
    .border({width:20,color:"#36D",radius:"200px"}) //修改圆角大小 
  } 
 
  build() { 
    Column() { 
      Button("transition modal 1") 
        .onClick(() => { 
          this.isShow = true 
        }) 
        .fontSize(20) 
        .margin(10) 
        .bindSheet($$this.isShow, this.myBuilder(), { 
          height: this.sheetHeight, 
          //把maskColor和backgroundColor设置一致 
          maskColor:Color.Red, 
          backgroundColor:Color.Red, 
          onAppear: () => {console.log("BindSheet onAppear.")}, 
          onDisappear: () => {console.log("BindSheet onDisappear.")} 
        }) 
    } 
    .justifyContent(FlexAlign.Center) 
    .width('100%') 
    .height('100%') 
  } 
}