如何快速开发出一个自定义弹窗？

@Entry
@Component
struct Index {
  //声明弹窗controller
  dialogController: CustomDialogController = new CustomDialogController({
    builder: MyDialog()
  })
  build() {
    Column() {
      Button().onClick(() => {
        //点击按钮，弹出弹窗
        this.dialogController.open()
      })
    }
    .width('100%')
    .height('100%')
    .justifyContent(FlexAlign.Center)
  }
}

//自定义弹窗
@CustomDialog
struct MyDialog {
  controller: CustomDialogController = new CustomDialogController({
    builder: MyDialog(),
  })

  build() {
    Column() {
      Text('我是弹窗内容内容')
        .fontSize(20)
        .margin({ top: 10, bottom: 10 })
    }
  }
}