我做了一个定制JComboBox
。为此,我使用了一个JPopupMenu
包含JCheckBoxMenuItem
. 但显然,在更改PopupMenuListener
popupMenuWillBecomeInvisible
之前正在运行。JCheckBoxMenuItem
任何想法如何解决?我不想在JCheckBoxMenuItem
.
public class ListenerTest extends JFrame implements ActionListener, PopupMenuListener {
private JPopupMenu menu;
private List<JCheckBoxMenuItem> menuItems;
private JCheckBoxMenuItem i1;
private JCheckBoxMenuItem i2;
private JCheckBoxMenuItem i3;
public ListenerTest(){
// Create button
JButton b = new JButton("Click me!");
b.addActionListener(this);
// Create Popupmenu
menu = new JPopupMenu();
menu.addPopupMenuListener(this);
// Add CheckBoxes to PopupMenu
menuItems = new LinkedList<JCheckBoxMenuItem>();
i1 = new JCheckBoxMenuItem("1");
i2 = new JCheckBoxMenuItem("2");
i3 = new JCheckBoxMenuItem("3");
menu.add(i1);
menu.add(i2);
menu.add(i3);
this.add(b);
this.setDefaultCloseOperation(EXIT_ON_CLOSE);
this.pack();
this.setVisible(true);
}
public static void main(String[] args){
new ListenerTest();
}
@Override
public void actionPerformed(ActionEvent e) {
// Show PopupMenu when button is clicked
menu.show(this, 0, this.getHeight());
}
@Override
public void popupMenuWillBecomeVisible(PopupMenuEvent e) {}
@Override
public void popupMenuWillBecomeInvisible(PopupMenuEvent e) {
// Check which checkBoxes is checked when popup menu is closed(currently one step behind)
System.out.println(i1.isSelected());
System.out.println(i2.isSelected());
System.out.println(i3.isSelected());
}
@Override
public void popupMenuCanceled(PopupMenuEvent e) {}
}