想问一下lockCanvas一直返回为null应该怎么解决?
canvas = mHolder.lockCanvas();
if (canvas != null) {
canvas.drawBitmap(bmp, (canvas.getWidth() - getmFrameWidth()) / 2, (canvas.getHeight() - getmFrameHeight()) / 2, null);
mHolder.unlockCanvasAndPost(canvas);
}