Comment faire SurfaceView avec un fond transparent?

J'ai mise en page simple

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/RelativeLayout1"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="@drawable/backgroundtimer"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/TextView1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:text="@string/hello" />

    <com.fmech.zenclock.surface.ZenClockSurface
        android:id="@+id/zenClockSurface1"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"/>

</RelativeLayout>

Et ZenClockSurface classe

package com.fmech.zenclock.surface;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.Paint.Style;
import android.graphics.PixelFormat;
import android.util.AttributeSet;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
public class ZenClockSurface extends SurfaceView implements SurfaceHolder.Callback{
private DrawClock drawClock;
public ZenClockSurface(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
this.getHolder().setFormat(PixelFormat.TRANSLUCENT);
getHolder().addCallback(this);
}
public ZenClockSurface(Context context) {
super(context);
this.getHolder().setFormat(PixelFormat.TRANSLUCENT);
getHolder().addCallback(this);
}
public ZenClockSurface(Context context, AttributeSet attrs) {
super(context, attrs);
this.getHolder().setFormat(PixelFormat.TRANSLUCENT);
getHolder().addCallback(this);
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {
//TODO Auto-generated method stub
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
//this.getHolder().setFormat(PixelFormat.TRANSPARENT);
drawClock = new DrawClock(getHolder(), getResources());
drawClock.setRunning(true);
drawClock.start();
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
boolean retry = true;
//завершаем работу потока
drawClock.setRunning(false);
while (retry) {
try {
drawClock.join();
retry = false;
} catch (InterruptedException e) {
}
}
}
class DrawClock extends Thread{
private boolean runFlag = false;
private SurfaceHolder surfaceHolder;
private Bitmap picture;
private Matrix matrix;
private long prevTime;
private Paint painter;
public DrawClock(SurfaceHolder surfaceHolder, Resources resources){
this.surfaceHolder = surfaceHolder;
this.surfaceHolder.setFormat(PixelFormat.TRANSLUCENT);
picture = BitmapFactory.decodeResource(resources, R.drawable.ic_launcher);
matrix = new Matrix();
this.painter=new Paint();
this.painter.setStyle(Paint.Style.FILL);
}
public void setRunning(boolean run) {
runFlag = run;
}
@Override
public void run() {
Canvas canvas;
while (runFlag) {
matrix.preRotate(1.0f, picture.getWidth() / 2, picture.getHeight() / 2);
canvas = null;
try {
//surfaceHolder.getSurface().setAlpha(0.5f);
canvas = surfaceHolder.lockCanvas(null);
synchronized (surfaceHolder) {
canvas.drawColor(Color.TRANSPARENT);
canvas.drawBitmap(picture, matrix, this.painter);
}
} 
finally {
if (canvas != null) {
surfaceHolder.unlockCanvasAndPost(canvas);
}
}
}
}
}
}

Et le code de l'activité

package com.fmech.zenclock.surface;
import android.app.Activity;
import android.graphics.PixelFormat;
import android.os.Bundle;
public class ZenClockSurfaceActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getWindow().setFormat(PixelFormat.TRANSLUCENT);
setContentView(R.layout.main);
}
}

Je veux que la couleur de fond de android photo a été tranparent mais j'obtiens un fond noir.

J'ai une formation sur RelativeLayout avec une certaine image de la bu SurfaceView faire tourner Android icône avec pas transparent.

Comment je peux le faire transparent?

OriginalL'auteur Dmitry Nelepov | 2011-12-05