Question

使用Wii Remote时，我的Java代码出现问题。我的情况是“当按钮A按下时，在屏幕上打印一些东西（在我的情况下是原始加速度）直到释放按钮A”，所以，经过几天的搜索，我使用TimerTask和Timer来完成任务。它打印了原始加速度。 Howerver，在我释放按钮A后，它无法停止打印。这是我的代码：

public class TestTimerTask implements WiimoteListener { 
    public RawAcceleration rawacc;    
    public static void main(String[] args){        
        Wiimote[] wiimotes = WiiUseApiManager.getWiimotes(1, true);
        Wiimote wiimote = wiimotes[0];
        wiimote.activateMotionSensing();
        wiimote.toString();
        wiimote.addWiiMoteEventListeners(new TestTimerTask ());  
    }
    @Override
    public void onButtonsEvent(WiimoteButtonsEvent wbe) {

        boolean check = false;
        Timer timer = new Timer();
        TaskNeedToDo task = new TaskNeedToDo();

        if(wbe.isButtonAJustReleased()){

            System.out.println("Button A Just Released");
            task.setCheck(false);
            task.cancel();
            timer.cancel();
        }

        if(wbe.isButtonAJustPressed()){
           // check = false;
            try {
                System.out.println("Button A Just Pressed");       
                DateFormat dateFormatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss:sss");
                Date temp = new Date (System.currentTimeMillis());


                Date now = dateFormatter.parse(dateFormatter.format(temp));


                int period = 300;
                task.setCheck(true);
                task.setRawAcc(rawacc);
                timer.schedule(task, 0, period);


            } catch (ParseException ex) {
               System.out.println("Error when take current time");
            }           

        }        

        if(wbe.isButtonBHeld())
            WiiUseApiManager.shutdown();
    }

    @Override
    public void onIrEvent(IREvent ire) {
         System.out.println("onIrEvent oocur");
    }

    @Override
    public void onMotionSensingEvent(MotionSensingEvent mse) {
        rawacc = mse.getRawAcceleration();
    }
     class TaskNeedToDo extends TimerTask {
    private boolean check;
    private RawAcceleration value;

    public boolean getCheck(){
        return check;
    }
    public void setCheck(boolean check){
        this.check = check;
        if(check == false)
            this.cancel();
    }
    public RawAcceleration getRawAcc(){
        return value;
    }
    public void setRawAcc(RawAcceleration value){
        this.value = value;
    }
    @Override
    public void run() {
        if(check == false)
            this.cancel();        

        System.out.println(value);
        System.out.println(check);
    }
}

结果如下：

Button A Just Pressed

Raw acceleration : (14, 115,148)

true

Raw acceleration : (14, 115,148)

true

Raw acceleration : (14, 115,148)

true

Button A Just Released

Raw acceleration : (14, 115,148)

true

Raw acceleration : (14, 115,148)

true

Raw acceleration : (14, 115,148)

true

Raw acceleration : (14, 115,148)

true

Raw acceleration : (14, 115,148

true

检查仍然是真的，所以它无法停止:( 谢谢你帮助我：D

Answer 1

当您呼叫timer.cancel()时，您正在新的计时器实例上调用它。因此，您不会取消之前安排的计时器。

我建议将计时器存储为类级别字段。确保它仅被实例化一次（使用new Timer()），然后确保在调用cancel时它与您调用schedule的实例相同。

Uber简化版：

public class TestTimerTask implements WiimoteListener { 

    private Timer timer = new Timer();

    @Override
    public void onButtonsEvent(WiimoteButtonsEvent wbe) {

        if(wbe.isButtonAJustReleased()) {
            timer.cancel();
        }

        if(wbe.isButtonAJustPressed()) {
            timer.schedule(...);
        }

    }

}

无法停止TimerTask

1 个答案: