get "black screen" when call unlockCanvasAndPost

by 鐒?鍒 » Thu, 02 Sep 2010 01:58:51 GMT


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 Hi!
The source code as an example :

        Canvas c=mHolder.lockCanvas(null);
        Paint paint=new Paint();
        paint.setColor(Color.DKGRAY);
        c.drawRect(new RectF(40,60,80,80), paint);
        mHolder.unlockCanvasAndPost(c);

My aim is to draw several graphics using lockCanvas and
unlockCanvasAndPost at different places controled by keydown event,but
each time when I press the key,the screen becomes black and only
drawing current graphics,when pressing the key again,the background
recoveryed.
So how to overcome this problem?

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