How to display an imagebutton on a surfaceview

Question

I want to draw a wave on a surfaceview when recording and show a ImageButton on the SurfaceView at the end. I used FrameLayout.

<FrameLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content" >

    <SurfaceView
        android:id="@+id/sfv"
        android:layout_width="match_parent"
        android:layout_height="130dp"
        android:background="#464646" />

    <ImageButton
        android:id="@+id/ib_delete"
        android:layout_width="40dp"
        android:layout_height="40dp"
        android:layout_gravity="center"
        android:visibility="gone"
        android:background="@drawable/record_delete" />

</FrameLayout>

At the end of recording, I use the method

ib_delete.setVisibility(View.VISIBLE)

But it does not work. How can I solve this problem？