所以我需要的功能是组合框,在展开时可以右键单击它,然后显示一个弹出菜单,显示不同的操作。
为此,我使用以下构造函数扩展了 JCombobox:
public HistoryComboBox(DefaultComboBoxModel model) {
super(model);
super.setUI(new BasicComboBoxUI(this){
@Override protected ComboPopup createPopup() {
return new HistoryComboPopup(comboBox);
}
});
并创建了扩展 BasicComboPopup 的 HistoryComboPopup 类,并有一个 mouselistener
@Override
protected MouseListener createListMouseListener() {
if (handler2 == null)
handler2 = new Handler2();
return handler2;
}
private class Handler2 implements MouseListener {
@Override
public void mouseClicked(MouseEvent e) {
JPopupMenu popup = new JPopupMenu();
...
popup.show();
}
}
弹出窗口有效,我可以处理它的菜单点击。唯一的问题是当我打开 JPopupMenu 时组合框关闭,并且不再看到我单击右键的项目。
我目前不知道该怎么做,所以任何帮助将不胜感激。
编辑:我混搭了一个可编译的例子:
public class MainPanel extends JPanel{
public MainPanel() {
super(new BorderLayout());
JComboBox combo1 = makeComboBox(5);
combo1.setUI(new BasicComboBoxUI() {
@Override protected ComboPopup createPopup() {
return new HistoryComboPopup(comboBox);
}
});
add(combo1,BorderLayout.NORTH);
}
private static JComboBox makeComboBox(int size) {
DefaultComboBoxModel model = new DefaultComboBoxModel();
for(int i=0;i<size;i++) {
model.addElement("No."+i);
}
return new JComboBox(model);
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
@Override public void run() {
JFrame frame = new JFrame("DisableRightClick");
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
frame.getContentPane().add(new MainPanel());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
}
class HistoryComboPopup extends BasicComboPopup {
private Handler2 handler2;
@Override
public void uninstallingUI() {
super.uninstallingUI();
handler2 = null;
}
public HistoryComboPopup(JComboBox combo) {
super(combo);
}
@Override
protected MouseListener createListMouseListener() {
if (handler2 == null)
handler2 = new Handler2();
return handler2;
}
private class Handler2 implements MouseListener {
@Override public void mouseEntered(MouseEvent e) {}
@Override public void mouseExited(MouseEvent e) {}
@Override public void mouseClicked(MouseEvent e) {}
@Override public void mousePressed(MouseEvent e) {}
@Override
public void mouseReleased(MouseEvent e) {
if (SwingUtilities.isRightMouseButton(e)) {
JPopupMenu popup = new JPopupMenu();
JMenuItem copymethod = new JMenuItem("copy");
copymethod.addMouseListener(new MouseAdapter() {
@Override
public void mousePressed(MouseEvent e) {
System.out.println("copy clicked");
}
});
popup.add(copymethod);
popup.show(HistoryComboPopup.this,
e.getXOnScreen() - HistoryComboPopup.this.getLocationOnScreen().x,
e.getYOnScreen() - HistoryComboPopup.this.getLocationOnScreen().y);
} else {
comboBox.setSelectedIndex(list.getSelectedIndex());
comboBox.setPopupVisible(false);
}
}
}
}