使用SurfaceView.unlockCanvasAndPost报错IllegalArgumentException

解决方法:在提交unlockCanvasAndPost判断是否为空！

public void run() {while (true) {synchronized (surfaceHolder) {try {canvas = surfaceHolder.lockCanvas();canvas.drawBitmap(BK, 0, 0, paint);canvas.drawBitmap(bk, 0, 0, paint);ondraw(canvas);} catch (Exception e) {} finally {<strong><span style="color:#ff0000;">if(canvas!=null)</span></strong>{surfaceHolder.unlockCanvasAndPost(canvas);}}}try {Thread.sleep(50);} catch (InterruptedException e) {e.printStackTrace();}}