Android问题我写了个贪吃蛇报这个错误

Question

Answer 1

代码：public class GameThread extends Thread {

private GameView view;
private SurfaceHolder holder;
public boolean pauseFlag = false;// 是否暂停

public GameThread(GameView view) {
    this.view = view;
    holder = view.getHolder();
}

@Override
public void run() {

    Canvas canvas;
    while (true) {
        canvas = null;
        if (!pauseFlag) {
            try {
                canvas = holder.lockCanvas();
                synchronized (holder) {
                    view.drawGame(canvas);
                }

            } finally {
                if (canvas != null) {
                    holder.unlockCanvasAndPost(canvas);
                }
            }

        }
        try {
            Thread.sleep(200);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

}