我正在制作一个文字处理器应用程序,以便练习Java,我希望这样当用户尝试关闭应用程序时,JFrame会出现要求保存更改。
我正在考虑setDefaultCloseOperation()但到目前为止我运气不佳。如果可能的话,我还希望用户点击窗口右上角的“X”。
答案 0 :(得分:12)
您可以将JFrame DefaultCloseOperation设置为DO_NOTHING,然后设置WindowsListener以获取close事件并执行您想要的操作。我会在几分钟后发布一个例子。
编辑:以下是示例:
public static void main(String[] args) {
final JFrame frame = new JFrame("Test Frame");
frame.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
frame.setSize(800, 600);
frame.addWindowListener(new WindowAdapter() {
//I skipped unused callbacks for readability
@Override
public void windowClosing(WindowEvent e) {
if(JOptionPane.showConfirmDialog(frame, "Are you sure ?") == JOptionPane.OK_OPTION){
frame.setVisible(false);
frame.dispose();
}
}
});
frame.setVisible(true);
}
答案 1 :(得分:4)
import java.awt.event.*;
import javax.swing.*;
public class QuickGuiTest {
public static void main(String[] args) {
Runnable r = new Runnable() {
@Override
public void run() {
final JFrame frame = new JFrame("Test Frame");
frame.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
frame.setSize(600, 400);
frame.addWindowListener(new WindowAdapter() {
@Override
public void windowClosing(WindowEvent e) {
int result = JOptionPane.showConfirmDialog(
frame, "Are you sure?");
if( result==JOptionPane.OK_OPTION){
// NOW we change it to dispose on close..
frame.setDefaultCloseOperation(
JFrame.DISPOSE_ON_CLOSE);
frame.setVisible(false);
frame.dispose();
}
}
});
frame.setVisible(true);
}
};
SwingUtilities.invokeLater(r);
}
}
答案 2 :(得分:3)
您必须向WindowListener
添加JFrame
。
在windowClosing
方法中,您可以提供所需的代码。
例如:
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.OK_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.OK_OPTION) {
System.exit(0);
}
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
ClosingFrame cf = new ClosingFrame();
}
});
}
}