基本的Java Swing，如何退出和处置您的应用程序/ JFrame

Z时代
2024-01-10
分类：问答

用这样的代码处理JFrame的好方法是什么？我想处理窗口出口和窗口关闭。

我知道我们不应该使用System.exit（）;

public class JavaCellularAutomataSquare {
  public static final String TITLE = "Cellular Automata - Squaring Example";
  private int maxWidth = 600;
  private int maxHeight = 600;
  public void launch() {    
    final JFrame frame = new JFrame(TITLE);   
    frame.setLocation(20, 20);    
    frame.setPreferredSize(new Dimension(maxWidth, maxHeight));
    frame.setResizable(false);
    frame.setFocusable(true);
    final JPanel panel = new JPanel();
    panel.setLocation(20, 20);
    panel.setVisible(true);
    panel.setPreferredSize(new Dimension(maxWidth, maxHeight));    
    panel.setFocusable(true);
    panel.setBackground(Color.white);
    // Panel setup, toggle visibility on frame
    frame.add(panel);
    frame.pack();
    frame.setVisible(true);    
  }
}

回答：

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class ClosingFrame extends JFrame {
    private JMenuBar MenuBar = new JMenuBar();
    private JFrame frame = new JFrame();
    private static final long serialVersionUID = 1L;
    private JMenu File = new JMenu("File");
    private JMenuItem Exit = new JMenuItem("Exit");
    public ClosingFrame() {
        File.add(Exit);
        MenuBar.add(File);
        Exit.addActionListener(new ExitListener());
        WindowListener exitListener = new WindowAdapter() {
            @Override
            public void windowClosing(WindowEvent e) {
                int confirm = JOptionPane.showOptionDialog(frame,
                        "Are You Sure to Close this Application?",
                        "Exit Confirmation", JOptionPane.YES_NO_OPTION,
                        JOptionPane.QUESTION_MESSAGE, null, null, null);
                if (confirm == JOptionPane.YES_OPTION) {
                    System.exit(0);
                }
            }
        };
        frame.addWindowListener(exitListener);
        frame.setDefaultCloseOperation(EXIT_ON_CLOSE);
        frame.setJMenuBar(MenuBar);
        frame.setPreferredSize(new Dimension(400, 300));
        frame.setLocation(100, 100);
        frame.pack();
        frame.setVisible(true);
    }
    private class ExitListener implements ActionListener {
        @Override
        public void actionPerformed(ActionEvent e) {
            int confirm = JOptionPane.showOptionDialog(frame,
                    "Are You Sure to Close this Application?",
                    "Exit Confirmation", JOptionPane.YES_NO_OPTION,
                    JOptionPane.QUESTION_MESSAGE, null, null, null);
            if (confirm == JOptionPane.YES_OPTION) {
                System.exit(0);
            }
        }
    }
    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                ClosingFrame cf = new ClosingFrame();
            }
        });
    }
}