在我的一个程序中,我想在用户尝试退出应用程序时出现对话框。用户必须选择保存程序的某个状态,而不是保存或取消退出操作。Java:如何取消应用程序退出
我试图第一和ONY找到一个解决办法写了这个,然后实现它:
import javax.swing.*;
import java.awt.Dimension;
import java.awt.event.*;
class WL implements WindowListener
{
private boolean statussaved;
private JFrame tframe;
WL (JFrame frame)
{
statussaved = false;
tframe = frame;
}
@Override public void windowActivated (WindowEvent w) { }
@Override public void windowClosed (WindowEvent w) { }
@Override public void windowDeactivated (WindowEvent w) { }
@Override public void windowDeiconified (WindowEvent w) { }
@Override public void windowIconified (WindowEvent w) { }
@Override public void windowOpened (WindowEvent w) { }
@Override public void windowClosing (WindowEvent w)
{
if (statussaved)
{
return;
}
final JDialog diag = new JDialog (tframe, "Save Progress", true);
diag.setPreferredSize (new Dimension (500, 100));
diag.setResizable (false);
diag.setDefaultCloseOperation (JDialog.DISPOSE_ON_CLOSE);
JPanel notifypanel = new JPanel();
notifypanel.add (new JLabel ("Do you want to save the current status ?"));
JButton yesbutton = new JButton ("Yes");
JButton nobutton = new JButton ("No");
JButton cancelbutton = new JButton ("Cancel");
yesbutton.addActionListener (new ActionListener()
{
@Override public void actionPerformed (ActionEvent a)
{
//SAVE THE STATUS
System.out.println ("Saving status...");
statussaved = true;
diag.dispose();
tframe.dispose();
}
});
nobutton.addActionListener (new ActionListener()
{
@Override public void actionPerformed (ActionEvent a)
{
//just exit/close the application
diag.dispose();
tframe.dispose();
}
});
cancelbutton.addActionListener (new ActionListener()
{
@Override public void actionPerformed (ActionEvent a)
{
//DON'T EXIT !!!
diag.dispose();
}
});
notifypanel.add (yesbutton);
notifypanel.add (nobutton);
notifypanel.add (cancelbutton);
diag.setContentPane (notifypanel);
diag.pack();
diag.setVisible (true);
}
}
public class SaveTest
{
public static void main (String[] args)
{
SwingUtilities.invokeLater (new Runnable()
{
@Override public void run()
{
JFrame frame = new JFrame ("Save Test");
frame.setDefaultCloseOperation (JFrame.DISPOSE_ON_CLOSE);
frame.addWindowListener (new WL (frame));
JLabel lab = new JLabel ("just some information");
frame.setPreferredSize (new Dimension (400, 300));
frame.setResizable (false);
frame.add (lab);
frame.pack();
frame.setVisible (true);
}
});
}
}
它编译并没有任何变化运行,所以你可以测试它。
“是”和“否”选项按预期工作,但我绝对不知道要在“取消”按钮的ActionListener
中写什么内容。我想要的是,当用户点击“取消”按钮时,对话消失,但主窗口保持可见(即程序保持运行)。
现在,因为这一切都是在windowClosing
方法来实现,它是一种明显,某种处置信号是为了摧毁JFrame
发送。这意味着目前的设计可能无法做到这一点。我不介意重组/重新设计所有这些以使其发挥作用。只是...我不知道如何。
任何想法?
谢谢,我只是这样做,它的作品:)。 PS:其实这个改变是针对'大型机'而不是'diag'。 – 2012-02-12 14:51:44