AndroidでSurfaceView を利用して背景を操作（Transparent/Translucent）するサンプル
1.Javaコード：
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);//透明 Transparent
//getHolder().setFormat(PixelFormat.TRANSLUCENT);//半透明 Translucent
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()));
}
}
2.AndroidManifest.xml
<?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″ /> <application android:icon="@drawable/icon" android:label="@string/app_name">
<activity android:name=".TransParentActivity"
android:label="Transparent SurfaceView"
android:theme="@android:style/Theme.Translucent"
>
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity> </application>
</manifest>