Question

Netbeans GUI中的JPopupMenu怎么用？

Answer 1

JMenuItem
add(JMenuItem menuItem)
将指定菜单项添加到此菜单的末尾。

JMenuItem
add(String s)
创建具有指定文本的菜单项，并将其添加到此菜单的末尾。

//...where instance variables are declared:
JPopupMenu popup;

//...where the GUI is constructed:
//Create the popup menu.
popup = new JPopupMenu();
menuItem = new JMenuItem("A popup menu item");
menuItem.addActionListener(this);
popup.add(menuItem);
menuItem = new JMenuItem("Another popup menu item");
menuItem.addActionListener(this);
popup.add(menuItem);

//Add listener to components that can bring up popup menus.
MouseListener popupListener = new PopupListener();
output.addMouseListener(popupListener);
menuBar.addMouseListener(popupListener);
...
class PopupListener extends MouseAdapter {
public void mousePressed(MouseEvent e) {
maybeShowPopup(e);
}

public void mouseReleased(MouseEvent e) {
maybeShowPopup(e);
}

private void maybeShowPopup(MouseEvent e) {
if (e.isPopupTrigger()) {
popup.show(e.getComponent(),
e.getX(), e.getY());
}
}
}