HarmonyOS 鸿蒙Next如何让CustomDialog的蒙层通过渐隐的方式展示，而弹框内容自底向上弹出

如何让CustomDialog的蒙层通过渐隐的方式展示，而弹框内容自底向上弹出

如果通过transition设置的话，蒙层和弹框内容会采用相同的动画效果

let anmDuration: number = 300;

// 弹窗交互
[@CustomDialog](/user/CustomDialog)
struct CustomDialogExample {
  controller: CustomDialogController = new CustomDialogController({
    builder: CustomDialogExample({}),
    autoCancel: false
  })
  [@State](/user/State) showFlag: Visibility = Visibility.Visible;
  [@State](/user/State) isAutoCancel: boolean = false;
  textController: TextAreaController = new TextAreaController()

  build() {
    Column() {
      Row() {
        Text("自定义动画的弹窗")
      }
      .borderRadius(20)
      .backgroundColor('#ff6288cb')
      .height(200)
      .width('100%')
    }
    .margin({ top: 10 })
    .justifyContent(FlexAlign.Center)
    .width('100%')
    .height("100%")
    .onClick(() => {
      console.log("dialogClick")
      if (this.isAutoCancel) {
        console.log("dialogClick2")
        this.cancel();
      }
    })
    .visibility(this.showFlag)
    // 定义进场出场转场动画效果
    .transition(TransitionEffect.OPACITY.animation({ duration: anmDuration })
      .combine(TransitionEffect.translate({ y: 500 })))
  }

  // 延迟关闭弹窗，让自定义的出场动画显示
  cancel() {
    this.showFlag = Visibility.Hidden
    console.log("closeDialog")
    setTimeout(() => {
      this.controller.close()
    }, anmDuration)
  }
}

[@Entry](/user/Entry)
[@Component](/user/Component)
struct CustomDialogUser {
  [@State](/user/State) isAutoCancel: boolean = true;
  dialogController: CustomDialogController = new CustomDialogController({
    builder: CustomDialogExample({ isAutoCancel: this.isAutoCancel }),
    autoCancel: this.isAutoCancel,
    customStyle: true,
  })

  build() {
    Column() {
      Button('click me')
        .onClick(() => {
          this.dialogController.open()
        })
    }.width('100%')
    .height('100%')
  }
}