Android SurfaceView 透明和半透明

<span style="font-size: 18px; color: #ff0000;">透明//Transparent
半透明//Translucent</span>

package rw.Trans;

import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.PixelFormat;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceHolder.Callback;
import android.view.SurfaceView;

public class TransParentActivity extends Activity {
    /** Called when the activity is first created. */
	class MySurfaceView extends SurfaceView implements Callback{
        float left,top;
        Bitmap bitmap=BitmapFactory.decodeResource(getResources(), R.drawable.reen);
		public MySurfaceView(Context context) {
			super(context);
			// TODO Auto-generated constructor stub
			<span style="color: #ff0000;">getHolder().setFormat(PixelFormat.TRANSPARENT);//设置为透明
			//getHolder().setFormat(PixelFormat.TRANSLUCENT);//半透明</span>
			getHolder().addCallback(this);
			setFocusable(true);
		}

		@Override
		public void surfaceChanged(SurfaceHolder holder, int format, int width,
				int height) {
			// TODO Auto-generated method stub
			
		}

		@Override
		public void surfaceCreated(SurfaceHolder holder) {
			// TODO Auto-generated method stub
		 doDraw();	
		}

		private void doDraw() {
			// TODO Auto-generated method stub
			Canvas canvas=getHolder().lockCanvas();
			canvas.drawBitmap(bitmap, left, top, null);
			getHolder().unlockCanvasAndPost(canvas);
		}

		@Override
		public void surfaceDestroyed(SurfaceHolder holder) {
			// TODO Auto-generated method stub
			
		}
		
		/* (non-Javadoc)
		 * @see android.app.Activity#onTouchEvent(android.view.MotionEvent)
		 */
		@Override
		public boolean onTouchEvent(MotionEvent event) {
			// TODO Auto-generated method stub
			left=event.getX();
			top=event.getY();
			doDraw();
			
			return super.onTouchEvent(event);
		}
	}
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(new MySurfaceView(getApplicationContext()));
        
    }
	
}

AndroidManifest.xml

<p><?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="<a href="http://schemas.android.com/apk/res/android">http://schemas.android.com/apk/res/android</a>"
 package="rw.Trans"
 android:versionCode="1"
 android:versionName="1.0">
 <uses-sdk android:minSdkVersion="10" /></p>
<p> <application android:icon="@drawable/icon" android:label="@string/app_name">
 <activity android:name=".TransParentActivity"
 android:label="Transparent SurfaceView"
<span style="color: #ff0000;"> android:theme="@android:style/Theme.Translucent"
</span> ></p>
<p> 
 <intent-filter>
 <action android:name="android.intent.action.MAIN" />
 <category android:name="android.intent.category.LAUNCHER" />
 </intent-filter>
 </activity></p>
<p> </application>
</manifest></p>