Spiel (zeichnen probleme)

public class GameView extends SurfaceView implements Runnable{


	Thread gameThread;
	boolean gameRunning;
	private SurfaceHolder sh;
	private Canvas c;
	private Bitmap ball;
	private Context context;
	private int xBall=50,yBall=50;
	
	public GameView(Context context, AttributeSet attrs) {
		super(context, attrs);
		this.context=context;
		sh=this.getHolder();
	}
	
	public void initializations() {
		c=new Canvas();
		
		
		
		ball = BitmapFactory.decodeResource(context.getResources(), R.drawable.ball);
		Paint p=new Paint(Color.BLUE);
		c.drawCircle(this.getWidth()/2f,this.getHeight()/2f,100f, p);
		c.drawARGB(0, 0, 0, 255);
	


	}
	


	


	@Override
	public void run() {
	Log.d("in Game View run","spiel gestarted"); 
	while(gameRunning){
		c=null;
		c=sh.lockCanvas(null);
		doDraw();
		if(c!=null){
			sh.unlockCanvasAndPost(c);
		}
	}
	
	}
	
	
	public void doDraw(){
		
		c.drawARGB(0, 0, 0, 255);
		c.drawBitmap(ball,xBall,yBall,new Paint());
	}
	
	public GameView getThis(){
		return this;
	}


}

public class GameLogic extends Activity {
	/** Called when the activity is first created. */
	@Override
	public void onCreate(Bundle savedInstanceState) {
    	super.onCreate(savedInstanceState);
    	setContentView(R.layout.main);
	
	}
	
	private static final int menuStart=Menu.FIRST,menuExit=Menu.FIRST+1;
	
	@Override
	public boolean onCreateOptionsMenu(Menu menu){
		menu.add(0,menuStart,0,"Start");
		menu.add(0,menuExit,0,"EXIT");
		return true;
	}
	
	private GameView gv;
	@Override
	public boolean onOptionsItemSelected(MenuItem mi) {
		switch(mi.getItemId()){
		case menuStart: Toast.makeText(this, R.string.game_started, Toast.LENGTH_LONG).show(); 
		gv=(GameView) findViewById(R.id.game);
		gv.gameRunning=true;
		gv.initializations();
		gv.gameThread=new Thread(gv);
		gv.gameThread.start();
		return true;
		case menuExit: System.exit(0); return true;
		}
		
	return false;
	}
	
	
}