在我的一个程序中,我希望在用户尝试退出应用程序时显示一个Dialog.然后,用户必须选择保存程序的某些状态,而不是保存或取消退出操作.
我写这个是为了首先找到解决方案,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); } }); } }
它编译和运行没有任何变化,所以你可以测试它.
“是”和“否”选项按预期工作,但我完全不知道在“取消”按钮的ActionListener中写什么.我想要的是,当用户点击“取消”按钮时,对话框消失,但主窗口仍然可见(即程序继续运行).
现在,由于所有这些都是在windowClosing方法中实现的,因此很明显发送了某种处理信号以破坏JFrame.这意味着在当前的设计中可能无法做到这一点.我不介意重新组织/重新设计所有这些以使其工作.它只是……我不知道如何.
有任何想法吗 ?