Button auf Canvas ohne Event-Reaktion

private class SensorGraphView extends View {


		private Bitmap mBitmap;
		private Canvas mCanvas;
    	private Paint mPaint;
    	Button button;


		protected SensorGraphView(Context context) {
			super(context);


			mPaint = new Paint();
		mPaint.setAntiAlias(true);
		mPaint.setDither(true);
		mPaint.setColor(0xFFFF0000);
		mPaint.setStyle(Paint.Style.STROKE);
		mPaint.setStrokeJoin(Paint.Join.ROUND);
		mPaint.setStrokeCap(Paint.Cap.SQUARE);
		mPaint.setStrokeWidth(1);


			mBitmap = Bitmap.createBitmap(320, 200, Bitmap.Config.ARGB_8888);
			mCanvas = new Canvas(mBitmap);
			mBitmapPaint = new Paint(Paint.DITHER_FLAG);
		   
			button = new Button(context);
			
		   }


		@Override
		protected void onDraw(Canvas canvas) {
			
			try{
			synchronized (this) {
				
				if (mBitmap != null) {


					canvas.drawColor(0xFFAAAAAA);
					canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);


		    	}
				
				int width = button.getMeasuredWidth();
				int height = button.getMeasuredHeight();
				int left = 60;
				int top = 60;
		   	button.measure(width, height);
				button.layout(left, top, left+width, top+height);


				button.draw(canvas);
				
				button.setOnClickListener(new OnClickListener() {
					
					public void onClick(View v) {
						button.setBackgroundColor(Color.RED);		
					}
				}); 


				invalidate();
			}
			}catch(Exception ex){
			   
			}
		}
	}