弹出菜单的创建与使用

import java.awt.BorderLayout;

import java.awt.Component;

import java.awt.EventQueue;

import java.awt.event.MouseAdapter;

import java.awt.event.MouseEvent;

import javax.swing.JFrame;

import javax.swing.JMenu;

import javax.swing.JMenuItem;

import javax.swing.JPanel;

import javax.swing.JPopupMenu;

import javax.swing.JSeparator;

import javax.swing.UIManager;

import javax.swing.UnsupportedLookAndFeelException;

import javax.swing.border.EmptyBorder;

import com.sun.java.swing.plaf.windows.WindowsLookAndFeel;

import java.awt.event.ActionListener;

import java.awt.event.ActionEvent;

import javax.swing.JCheckBoxMenuItem;

import javax.swing.JRadioButtonMenuItem;

public class MyFrame extends JFrame {

private JPanel contentPane;

JPopupMenu popupMenu;

/**

* Launch the application.

*/

public static
void main(String[] args) {

EventQueue.invokeLater(new Runnable() {

public
void run() {

try {

MyFrame frame = new MyFrame();

frame.setVisible(true);

} catch (Exception e) {

e.printStackTrace();

}

}

});

}

/**

* Create the frame.

*/

public MyFrame() {

//设定成 Windows 样式的 LookAndFeel

try {

UIManager.setLookAndFeel(new WindowsLookAndFeel());

} catch (UnsupportedLookAndFeelException e) {

e.printStackTrace();

}

setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

setBounds(100, 100, 450, 300);

contentPane = new JPanel();

contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));

setContentPane(contentPane);

contentPane.setLayout(new BorderLayout(0, 0));

//手动为 contentPane 添加鼠标点击事件：鼠标左键点击弹框

contentPane.addMouseListener(new MouseAdapter() {

@Override

public
void mouseClicked(MouseEvent e) {

//指明调用者，显示弹框的 X Y 坐标即点击的位置

popupMenu.show(MyFrame.this, e.getX(), e.getY());

}

});

//将 popupMenu 的声明转移到类中

popupMenu = new JPopupMenu();

//可以将 JPopupMenu 添加到 contentPane 中，也可以不添加

//将下面的 addPopup() 注释掉即不添加

addPopup(contentPane, popupMenu);

JMenuItem mntmX = new JMenuItem("X");

popupMenu.add(mntmX);

JMenuItem mntmY = new JMenuItem("Y");

popupMenu.add(mntmY);

JMenuItem mntmZ = new JMenuItem("Z");

popupMenu.add(mntmZ);

//分隔线，可以使用代码手动实现，

//也可以使用控件（组件） JSeparator 拖动实现

JSeparator separator = new JSeparator();

popupMenu.add(separator);

JMenu mnNum = new JMenu("Num");

popupMenu.add(mnNum);

JMenuItem menuItem = new JMenuItem("1");

mnNum.add(menuItem);

JMenuItem menuItem_1 = new JMenuItem("2");

mnNum.add(menuItem_1);

JMenuItem menuItem_2 = new JMenuItem("3");

mnNum.add(menuItem_2);

JSeparator separator_1 = new JSeparator();

popupMenu.add(separator_1);

JMenuItem mntmClose = new JMenuItem("Close");

//对菜单项：Close 添加 actionPerformed 事件

//点击 Close 关闭程序（注意：添加鼠标点击事件无效）

mntmClose.addActionListener(new ActionListener() {

public
void actionPerformed(ActionEvent e) {

System.exit(0);

}

});

JCheckBoxMenuItem chckbxmntmC1 = new JCheckBoxMenuItem("C1");

chckbxmntmC1.setSelected(true);

popupMenu.add(chckbxmntmC1);

JCheckBoxMenuItem chckbxmntmC2 = new JCheckBoxMenuItem("C2");

popupMenu.add(chckbxmntmC2);

JRadioButtonMenuItem rdbtnmntmR1 = new JRadioButtonMenuItem("R1");

rdbtnmntmR1.setSelected(true);

popupMenu.add(rdbtnmntmR1);

JRadioButtonMenuItem rdbtnmntmR2 = new JRadioButtonMenuItem("R2");

popupMenu.add(rdbtnmntmR2);

popupMenu.add(mntmClose);

}

//这是将 JPopupMenu 添加到 contentPane 中，自动生成的代码

private static
void addPopup(Component component, final JPopupMenu popup) {

component.addMouseListener(new MouseAdapter() {

//鼠标右键点击弹框

public
void mousePressed(MouseEvent e) {

if (e.isPopupTrigger()) {

showMenu(e);

}

}

//鼠标右键点击弹框

public
void mouseReleased(MouseEvent e) {

if (e.isPopupTrigger()) {

showMenu(e);

}

}

private
void showMenu(MouseEvent e) {

popup.show(e.getComponent(), e.getX(), e.getY());

}

});

}

}