JAVA中Icon接口的应用（以JLabel为例）

This example shows the drawing of an icon using the Icon interface for the JLable component.

package com.han;
import java.awt.*;
import javax.swing.*;

/**
 * This example shows the drawing of an icon using the Icon interface
 *  for the JLable component.
 * @author han
 *
 */
public class DrawIcon implements Icon{
	private int width;
	private int height;
	@Override
	public int getIconHeight(){
		return this.height;
	}
	@Override
	public int getIconWidth(){
		return this.width;
	}
	@Override
	public void paintIcon(Component c, Graphics g, int x, int y){
		g.setColor(Color.red);
		g.fillOval(x, y, width, height);
	}
	/*the construct function*/
	public DrawIcon(int width, int height){
		this.width=width;
		this.height=height;
	}
    public static void main(String[] args){
    	DrawIcon icon=new DrawIcon(15,15);
    	JLabel jl=new JLabel("测试",icon,SwingConstants.CENTER);
    	JFrame jf=new JFrame();
    	Container c=jf.getContentPane();
    	c.add(jl);
    	jf.setVisible(true);
    	jf.setSize(300,300);
    	jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
}