JFrame的彈出式關閉按鈕

Question

我正在做一些基本的Java Swing application（初學者級別）。 什麼，我要做的就是當我按下close button on JFrame到colse的窗口，我想一個JOptionPane Confirm Dialog，而不是直接的密切

這裏是代碼的JFrame

JFrame frame= new JFrame("frame"); 
    frame.setSize(300,300); 
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
    frame.setVisible(true); 
    frame.pack(); 

和JOptionPane的代碼是這樣

final JOptionPane optionPane = new JOptionPane("Are You sure?",JOptionPane.QUESTION_MESSAGE, 
JOptionPane.YES_NO_OPTION); 

所以當關閉按鈕上JFrame按下這個彈出應該出來而不是直接關閉
請指導我如何做到這一點..謝謝提前

Answer 1

您可以通過以下步驟來做到：

1. 替換行frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);與frame.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);

2. 實施WindowListener並覆蓋其所有AB stract方法。你可以find it here。

3. 覆蓋的public void windowClosing(WindowEvent e)一些方法是這樣的：

   @Override 
   public void windowClosing(WindowEvent e){ 
        int result = JOptionPane.showConfirmDialog(null, "Are you sure,"Confirm",JOptionPane.YES_NO_OPTION,JOptionPane.QUESTION_MESSAGE); 
   
        if(result == JOptionPane.YES_OPTION){ 
          System.exit(0); 
        }else{ 
          //Do nothing 
        } 
   } 
   

Answer 2

是的，你可以通過使用WindowListener來做到這一點。

public void windowClosed(WindowEvent e) { 
     //This will only be seen on standard output. 
     displayMessage("WindowListener method called: windowClosed."); 
    } 

    public void windowOpened(WindowEvent e) { 
     displayMessage("WindowListener method called: windowOpened."); 
    } 

    public void windowIconified(WindowEvent e) { 
     displayMessage("WindowListener method called: windowIconified."); 
    } 

    public void windowDeiconified(WindowEvent e) { 
     displayMessage("WindowListener method called: windowDeiconified."); 
    } 

    public void windowActivated(WindowEvent e) { 
     displayMessage("WindowListener method called: windowActivated."); 
    } 

    public void windowDeactivated(WindowEvent e) { 
     displayMessage("WindowListener method called: windowDeactivated."); 
    } 

    public void windowGainedFocus(WindowEvent e) { 
     displayMessage("WindowFocusListener method called: windowGainedFocus."); 
    } 

    public void windowLostFocus(WindowEvent e) { 
     displayMessage("WindowFocusListener method called: windowLostFocus."); 
    } 

    public void windowStateChanged(WindowEvent e) { 
     displayStateMessage(
      "WindowStateListener method called: windowStateChanged.", e); 

請參閱this tutorial進一步的細節。
但對於你的情況，我建議你使用適配器類工作（因爲你只需要一個事件，因此不需要厭倦，並實現所有方法），所以這裏是根據您的需求量的一個例子

import java.awt.event.WindowAdapter; 
import java.awt.event.WindowEvent; 
import javax.swing.JFrame; 
import javax.swing.JOptionPane; 

public class NoCloseFrame extends JFrame { 
    public static void main(String[] arg) { 
     new NoCloseFrame(); 
    } 

    public NoCloseFrame() { 
     super("No Close Frame!"); 
     setDefaultCloseOperation(DO_NOTHING_ON_CLOSE); 
     setSize(300, 300); 
     setVisible(true); 
     addWindowListener(new AreYouSure()); 
    } 

    private class AreYouSure extends WindowAdapter { 
     public void windowClosing(WindowEvent e) { 
      int option = JOptionPane.showOptionDialog( 
        NoCloseFrame.this, 
        "Are you sure you want to quit?", 
        "Exit Dialog", JOptionPane.YES_NO_OPTION, 
        JOptionPane.WARNING_MESSAGE, null, null, 
        null); 
      if(option == JOptionPane.YES_OPTION) { 
       System.exit(0); 
      } 
     } 
    } 
}