Java JPopupMenu

本文概述

• JPopupMenu类声明
• Java JPopupMenu示例
• 带有MouseListener和ActionListener的Java JPopupMenu示例

PopupMenu可以在组件内的特定位置动态弹出。它继承了JComponent类。

JPopupMenu类声明

我们来看一下javax.swing.JPopupMenu类的声明。

public class JPopupMenu extends JComponent implements Accessible, MenuElement

常用的构造函数：

Java JPopupMenu示例

import javax.swing.*;
import java.awt.event.*;
class PopupMenuExample
{
	 PopupMenuExample(){
         final JFrame f= new JFrame("PopupMenu Example");
         final JPopupMenu popupmenu = new JPopupMenu("Edit"); 
         JMenuItem cut = new JMenuItem("Cut");
         JMenuItem copy = new JMenuItem("Copy");
         JMenuItem paste = new JMenuItem("Paste");
         popupmenu.add(cut); popupmenu.add(copy); popupmenu.add(paste);      
         f.addMouseListener(new MouseAdapter() {
            public void mouseClicked(MouseEvent e) {            
            	popupmenu.show(f , e.getX(), e.getY());
            }               
         });
         f.add(popupmenu); 
         f.setSize(300, 300);
         f.setLayout(null);
         f.setVisible(true);
	 }
public static void main(String args[])
{
        new PopupMenuExample();
}}

输出：

带有MouseListener和ActionListener的Java JPopupMenu示例

import javax.swing.*;
import java.awt.event.*;
class PopupMenuExample 
{
	 PopupMenuExample(){
         final JFrame f= new JFrame("PopupMenu Example");
         final JLabel label = new JLabel();        
         label.setHorizontalAlignment(JLabel.CENTER);
         label.setSize(400, 100);
         final JPopupMenu popupmenu = new JPopupMenu("Edit"); 
         JMenuItem cut = new JMenuItem("Cut");
         JMenuItem copy = new JMenuItem("Copy");
         JMenuItem paste = new JMenuItem("Paste");
         popupmenu.add(cut); popupmenu.add(copy); popupmenu.add(paste);      
         f.addMouseListener(new MouseAdapter() {
            public void mouseClicked(MouseEvent e) {            
            	popupmenu.show(f , e.getX(), e.getY());
            }               
         });
        cut.addActionListener(new ActionListener(){
         public void actionPerformed(ActionEvent e) {            
             label.setText("cut MenuItem clicked.");
         }
        });
        copy.addActionListener(new ActionListener(){
            public void actionPerformed(ActionEvent e) {            
                label.setText("copy MenuItem clicked.");
            }
           });
        paste.addActionListener(new ActionListener(){
            public void actionPerformed(ActionEvent e) {            
                label.setText("paste MenuItem clicked.");
            }
           });
         f.add(label); f.add(popupmenu); 
         f.setSize(400, 400);
         f.setLayout(null);
         f.setVisible(true);
	 }
public static void main(String args[])
{
        new PopupMenuExample();
}
}

输出：