当时，我试着用这个，但没有工作。

val surfaceView = RtcEngine.CreateRendererView(baseContext)
        surfaceView.apply {
            clipToOutline = true
            clipBounds = Rect(15,15, 15, 15)
            outlineProvider = CircularOutlineProvider(15)
            setZOrderMediaOverlay(true)
        }
        binding.localVideoViewContainer.apply {
            addView(surfaceView)
            clipToOutline = true
            clipBounds = Rect(15,15, 15, 15)
            outlineProvider = CircularOutlineProvider(15)
        }

class CircularOutlineProvider(val c: Int):ViewOutlineProvider() {
  override fun getOutline(view:View, outline:Outline) {
    outline.setRoundRect(c, c, view.width - c, view.height - c, view.width/2f)
  }
}

<FrameLayout
    android:id="@+id/local_video_view_container"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:clipChildren="true"
    android:clipToOutline="true"
    tools:background="@color/gray_7f"/>

我甚至试过用这样的可绘制文件设置背景，但没有工作。

<?xml version="1.0" encoding="UTF-8"?> 
<shape xmlns:android="http://schemas.android.com/apk/res/android"> 
    <solid android:color="#CCCCCC"/>    
    <stroke android:width="2dp"
        android:color="#999999"/>
    <padding android:left="2dp"
         android:top="2dp"
         android:right="2dp"
         android:bottom="2dp"/> 
    <corners android:radius="8dp" />
</shape>

<FrameLayout
    android:width="match_parent"
    android:height="wrap_content"
    android:background="@drawable/rounded_shape"/>

另外，WebView也有类似的问题。这有关系吗