android - how to make surfaceview transparent

Question

Hello all i want to make my DrawingSurface view transparent. i tried many thing but it's not working.

Here is my xml code to make my surface view transparent

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <FrameLayout
        android:layout_width="fill_parent"
        android:layout_height="fill_parent" >

        <ImageView
            android:id="@+id/imageView1"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:src="@drawable/icon" >
        </ImageView>

        <LinearLayout
            android:id="@+id/linearLayout1"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:background="#00000000" >

            <codewalla.android.drawings.DrawingSurface
                android:id="@+id/drawingSurface"
                android:layout_width="fill_parent"
                android:layout_height="fill_parent" >
            </codewalla.android.drawings.DrawingSurface>
        </LinearLayout>
    </FrameLayout>

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal" >

        <Button
            android:id="@+id/colorRedBtn"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_weight="10"
            android:onClick="onClick"
            android:text="R" />

        <Button
            android:id="@+id/colorBlueBtn"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_weight="10"
            android:onClick="onClick"
            android:text="G" />

        <Button
            android:id="@+id/colorGreenBtn"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_weight="10"
            android:onClick="onClick"
            android:text="B" />

        <Button
            android:id="@+id/undoBtn"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_weight="10"
            android:onClick="onClick"
            android:text="U" />

        <Button
            android:id="@+id/redoBtn"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="10"
            android:onClick="onClick"
            android:text="R" />
    </LinearLayout>

</RelativeLayout>

Answer 1

Try this in the constructor:

SurfaceView sfvTrack = (SurfaceView)findViewById(R.id.sfvTrack);
sfvTrack.setZOrderOnTop(true);    // necessary
SurfaceHolder sfhTrackHolder = sfvTrack.getHolder();
sfhTrackHolder.setFormat(PixelFormat.TRANSPARENT);