java - 倒计时器？

Question

我制作了一个简单的应用程序，其中包含测验问题，用户选择一个答案，但我需要您的帮助在我的应用程序中添加一个 20 秒的倒计时器，当该时间到时，它将直接转移到下一个问题，并且当用户及时回答时，它将转移到下一个问题

谢谢

Answer 1

import java.awt.BorderLayout; 
import java.awt.event.ActionEvent; 
import java.awt.event.ActionListener; 

import javax.swing.JFrame; 
import javax.swing.JLabel; 
import javax.swing.Timer; 
import javax.swing.WindowConstants; 


public class Countdown extends JFrame { 

  // Countdown 42 seconds 
  public static int counterValue = 42; 
  public static Timer timer; 
  public static JLabel label; 

  public Countdown() { 
    initGUI(); 
  } 

  private void initGUI(){ 
    BorderLayout thisLayout = new BorderLayout(); 
    this.setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE); 
    this.getContentPane().setLayout(thisLayout); 
    label = new JLabel(); 
    label.setText(String.valueOf(counterValue)); 
    this.getContentPane().add(label, BorderLayout.CENTER); 
    this.setTitle("Countdown Example"); 
      this.pack(); 
      this.setVisible(true); 
  } 


  public static void main(String[] args) { 
    Countdown countdown = new Countdown(); 


    Countdown.timer = new Timer(1000, new ActionListener() { 

      public void actionPerformed(ActionEvent e) { 
        // =1 sec
        Countdown.counterValue--; 

        Countdown.label.setText(String.valueOf(counterValue)); 


        if(Countdown.counterValue == 0){ 
          System.out.println("Counterdown ausgelaufen!"); 

          // Timer stop
          Countdown.timer.stop(); 
        } 
      } 
    }); 

    // Timer start
    timer.start(); 
  } 
}

取自 http://blog.mynotiz.de/programmieren/java-countdown-und-timer-am-beispiel-von-swing-1707/ (德语)