J2se Swing JOptionPane应用：对话框，启动，关

      
         1:  
      
      
        import 
      
      java.awt.event.WindowAdapter;
    

      
         2:  
      
      
        import 
      
      java.awt.event.WindowEvent;
    

      
         3:  
      
    

      
         4:  
      
      
        import 
      
      javax.swing.JFrame;
    

      
         5:  
      
      
        import 
      
      javax.swing.JOptionPane;
    

      
         6:  
      
      
        import 
      
      javax.swing.WindowConstants;
    

      
         7:  
      
    

      
         8:  
      
      
        public class 
      
      TestJDialog {
    

      
         9:  
      
    

      
        10:  
      
      
        public static void 
      
      main(String[] args) {
    

      
        11:  
      
              JOptionPane.showMessageDialog(
      
        null
      
      , 
      
        "程序开始启动"
      
      );
    

      
        12:  
      
      
        // 要被内置类访问，所以定义成fianl
      
    

      
        13:  
      
      
      
      
        final 
      
      JFrame f = 
      
        new 
      
      JFrame(
      
        "TestJDialog"
      
      );
    

      
        14:  
      
      
        // 当用户在点击JFrame上的关闭窗口按键时，JFrame会自动隐藏这个框架窗口，
      
    

      
        15:  
      
      
                // 但没有真正关闭这个窗口，还在内存中，我们要调用windowClosing，
      
    

      
        16:  
      
      
                // 或用下面的方法
      
    

      
        17:  
      
      
      
      f.setDefaultCloseOperation(WindowConstants.
      
        DO_NOTHING_ON_CLOSE
      
      );
    

      
        18:  
      
              f.addWindowListener(
      
        new 
      
      WindowAdapter() {
    

      
        19:  
      
    

      
        20:  
      
      
        @Override
      
    

      
        21:  
      
      
      
      
        public void 
      
      windowClosing(WindowEvent e) {
    

      
        22:  
      
      
        super
      
      .windowClosing(e);
    

      
        23:  
      
      
        int 
      
      retval = JOptionPane.showConfirmDialog(f, 
      
        "你真的要结束吗？"
      
      ,
    

      
        24:  
      
      
        "结束程序"
      
      , JOptionPane.
      
        YES_NO_OPTION
      
      );
    

      
        25:  
      
      
        if 
      
      (retval == JOptionPane.
      
        YES_OPTION
      
      ) {
    

      
        26:  
      
                          System.exit(0);
    

      
        27:  
      
                      }
    

      
        28:  
      
                  }
    

      
        29:  
      
              });
    

      
        30:  
      
              f.setSize(200, 200);
    

      
        31:  
      
              f.setVisible(
      
        true
      
      );
    

      
        32:  
      
          }
    

      
        33:  
      
    

      
        34:  
      
      }