jpopupmenudemo.java

Swing入门必看 Swing Demo

package components;

import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;

import javax.swing.ButtonGroup;
import javax.swing.JFrame;
import javax.swing.JPopupMenu;
import javax.swing.JRadioButtonMenuItem;

public class JPopupMenuDemo extends JFrame {

	private static final long serialVersionUID = 1L;
	private JPopupMenu popupMenu;
	private JRadioButtonMenuItem[] colors;
	private static final Color[] colorValues = {Color.RED,Color.GREEN,Color.BLUE};
	public JPopupMenuDemo() {
		
		popupMenu = new JPopupMenu();
		colors = new JRadioButtonMenuItem[3];
		String[] colorNames = {"RED","GREEN","BLUE"};
		ButtonGroup group = new ButtonGroup();
		ItemHandler handler = new ItemHandler();
		for (int i = 0; i < colors.length; i++) {
			colors[i] = new JRadioButtonMenuItem(colorNames[i]);
			colors[i].addActionListener(handler);
			popupMenu.add(colors[i]);
			group.add(colors[i]);
		}		
		addMouseListener(new MouseAdapter() {
			public void mouseReleased(MouseEvent e) {
				if(e.isPopupTrigger()) {
					popupMenu.show(e.getComponent(), e.getX(), e.getY());
				}
			}
		});
		
		setSize(400,400);
		setVisible(true);
	}
	public static void main(String[] args) {
		JPopupMenuDemo application = new JPopupMenuDemo();
		application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

	}
	class ItemHandler implements ActionListener {
		public void actionPerformed(ActionEvent e) {
			for(int i = 0; i < colors.length; i++) {
				if(colors[i] == e.getSource()) {
					getContentPane().setBackground(colorValues[i]);
				}
			}
		}
	}

}