如何为恢复按钮创建TimerTask的新实例？ （错误：TimerTask已经安排好了）

Question

早上好！我正在尝试为游戏设置一个暂停按钮，但是当我想恢复游戏时，再次初始化计时器任务时遇到了问题。

我收到错误“ java.lang.IllegalStateException：TimerTask已被调度”，根据我的研究，这是因为TimerTask无法重用，因此必须为其创建新实例。我尝试在MainActivity中创建一个可用于此目的的方法，但是该方法不起作用。这就是我正在使用的：

public class MainActivity extends AppCompatActivity{
    public FishView gameView;

    //pause variables
    Button pauseButton;
    private boolean pauseFlag = false;

    private final long animationPeriod = 600;
    Timer movementTimer;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        screen = findViewById(R.id.gameScreen);
        gameView = new FishView(this);
        screen.addView(gameView);

        pauseButton = findViewById(R.id.pauseButton);

        movementTimer = new Timer();
        movementTimer.scheduleAtFixedRate(animationTask, 0, animationPeriod);
    }

    //this is the timer I want to reuse 
    private TimerTask animationTask = new TimerTask() {
        @Override
        public void run() {
            handler.post(new Runnable() {
                @Override
                public void run() {
                    //set animation
                    int selectedFish = gameView.getSelectedFish();
                    if (selectedFish==1){
                        gameView.setSelectedFish(0);}
                    if (selectedFish==0){
                        gameView.setSelectedFish(1); }

                    //update screen
                    gameView.invalidate();

                }
            });
        }
    };


     public void pauseGame(View v){
        String resume = "Resume";
        String pause = "Pause";
        if (!pauseFlag){
            System.out.println("Turning timer of");
            pauseFlag = true;
            pauseButton.setText(resume);
            movementTimer.cancel();
            movementTimer=null;
        }
        else{
            System.out.println("Starting timer again");
            pauseFlag=false;
            pauseButton.setText(pause);
            try{
                movementTimer = new Timer();
                TimerTask newAnimationTask; //this did not work
                createNewAnimationTask(newAnimationTask); //this did not work
                movementTimer.scheduleAtFixedRate(animationTask, 0, animationPeriod); //here is where the error occurs
}
            catch (Exception e){
                System.out.println("ERROR: " + e);}

        }
    }

   //attempted to make method that would generate new TimerTasks
   public void createNewAnimationTask(TimerTask newAnimationTask){
        newAnimationTask = new TimerTask() {
        @Override
        public void run(){
            handler.post(new Runnable() {
                @Override
                public void run() {
                    System.out.println("Animation at work");
                    //here we set the animation
                    int selectedFish = gameView.getSelectedFish();
                    if (selectedFish==1){
                        gameView.setSelectedFish(0);}
                    if (selectedFish==0){
                        gameView.setSelectedFish(1); }

                    //update screen
                    gameView.invalidate();

                }
            });
        }
    };
    }



}

我想知道的是，每当我按下恢复按钮时，如何创建一个新的TimerTask（例如“ animationTask”）？

Answer 1

尝试像这样添加purge命令；

movementTimer.cancel(); 
movementTimer.purge();

Answer 2

我解决了。我删除了所有TimerTask并只是在函数中创建了所有内容，如下所示：

public void createNewAnimationTask(){
        movementTimer = new Timer();
        TimerTask newAnimationTask = new TimerTask() {
            @Override
            public void run() {
                handler.post(new Runnable() {
                    @Override
                    public void run() {
                        System.out.println("Animation at work");
                        //here we set the animation
                        int selectedFish = gameView.getSelectedFish();
                        if (selectedFish==1){
                            gameView.setSelectedFish(0);}
                        if (selectedFish==0){
                            gameView.setSelectedFish(1); }

                        //update screen
                        gameView.invalidate();
                    }
                });
            }
        };
        movementTimer.scheduleAtFixedRate(newAnimationTask, 0, animationPeriod);
    }