Question

我在理解Java中的接口/监听器时显然遇到了问题。（红色的Java新手警报）。使用https://docs.oracle.com/javase/7/docs/api/javax/swing/Timer.html和接口示例，我从timer.stop获取我不理解的行为，和/或从计时器中删除actionlisteners（即，触发'tick'）。无论我做什么，我都无法在使用界面等时停止计时器 - 我只能让它在本地课程中使用=意大利面条代码。

public void actionPerformed(ActionEvent e) {
    SimpleDateFormat sdf = new SimpleDateFormat("mm:ss");
    JButton clicked= (JButton) e.getSource();
    ClockLabel mainsClockList= new ClockLabel(mainsLab);

    if (clicked==clock1But) {
        /////////  Clock not started
        if  (mainsRunning==false)  {
            //mainsClockList = new ClockLabel(mainsLab);     // that starts 
                                                // it, wait for FB in listnr

            mainsClockList.setStopWatchListener(new StopWatchListener() {
                public void clockCount(long count)  {
                    System.out.println("Clock fired");     // fired every 
                                          //click- should only be on attach
                                        //  multiple calls button or EL?
                    mainsLab.setText(sdf.format(count));

                }
            });
            clock1But.setText("Stop");
            mainsRunning=true;
        }
        //// clock already started
        else if  (mainsRunning== true)  {
            System.out.println("in butt pressed already run");
            mainsClockList.stopClock();
            mainsClockList.setEnabled(false);
            mainsRunning=false;

        }



    }

    else if  (clicked==clock2But)   {           
        System.out.println("Got 2nd but");   }
    else if  (clicked==clock3But)   {       
        System.out.println("Got 3rd but");   }
}

Clock Lab课程： -

public ClockLabel(JLabel labIn) {       
    sdf = new SimpleDateFormat("mm:ss");
    t= new Timer(500, this );
    t.start();

}

public void actionPerformed(ActionEvent e) {    
    // this is listener for t....       
    Date d= new Date();
    long diff=  d.getTime() -cStarted.getTime();
    swListener.clockCount(diff);
}
public void stopClock()     {
    System.out.println("In CL, called stopclock");
    t.stop();                                   // no effect
    swListener= null;                       // no effect
    System.out.println("swListener := null");   
    // swListener.wait(5000);                null pointer on try catch so 
                                             //has killed sw....!
}

public void setStopWatchListener(StopWatchListener listener) {
    this.swListener= listener;
}

}

Interface

public interface StopWatchListener {
    public void clockCount(long count);
}

我尝试尽量减少代码，但请继续提供帮助。感谢任何指针，非常感谢。系统输出如下，只需单击1按钮即可开始，一个停止：

时钟已解雇时钟被解雇时钟被解雇时钟被解雇在对接已按下已经运行在CL中，称为stopclock swListener：= null 时钟被解雇时钟被解雇时钟被解雇时钟被解雇

Java swing timer-timer.stop（）with actionListeners＆amp;接口

0 个答案: