Is there a way to extract a Canvas or Bitmap from a View?

I have this class that extends View and draws a line:

public class MyDraw extends View 
{

    Paint paint = new Paint();

    public MyDraw(Context context) 
    {
        super(context);
        paint.setColor(Color.BLUE);
    }

    @Override
    public void onDraw(Canvas canvas) 
    {
    开发者_JAVA技巧    super.onDraw(canvas);
        canvas.drawLine(1, 1, 100, 100, paint);
    }
}

I would like to use the existing view from the Context to draw on top of it. Is it possible?

If you are just trying to get the view as a bitmap, you can get it from the drawing cache. This should work.

view.buildDrawingCache;
Bitmap bm = view.getDrawingCache

You cannot use the exisitng view instance and add it again as it already has a parent assigned to it and it wil cause an exception.