JAVA GUI学习 - 窗口【x】按钮关闭事件触发器：重写processWindowEvent(WindowEvent e)方法

 public class WindowListenerKnow extends JFrame
 {
     public WindowListenerKnow()
     {
         this.setBounds(300, 100, 400, 400);
         this.setTitle("我是测试【x】按钮关闭方法的");
         this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
     }
     public void init()
     {

     }
     public static void main(String[] args)
     {
         WindowListenerKnow windowListenerKnow = new WindowListenerKnow();
         windowListenerKnow.setVisible(true);
     }

     /**
      * 这里需要重写窗口的事件中转方法，而不是实现WindowListener接口，因为程序时从这个方法processWindowEvent进入到窗口关闭事件的
      */
     @Override
     protected void processWindowEvent(WindowEvent e)
     {
         //这里需要对进来的WindowEvent进行判断，因为，不仅会有窗口关闭的WindowEvent进来，还可能有其他的WindowEvent进来
         if (e.getID() == WindowEvent.WINDOW_CLOSING)
         {
             int option = JOptionPane.showConfirmDialog(null, "是否关闭程序？", "程序退出提示", JOptionPane.OK_CANCEL_OPTION);
             if (option == JOptionPane.OK_OPTION)
             {
                 super.processWindowEvent(e);
             }
             else {
                 //用户选择不退出本程序，因此可以继续留在本窗口
             }
         }
         else {
             super.processWindowEvent(e);
         }
     }
 }