带背景图片的JPanel

说明：本实例实现了两种背景图片的设置方法：

1，小幅图片自动复制多张填充整个背景。

2，大幅图片一张图填充整个背景。

 

package cn.xcu.ui;

import java.awt.Dimension;
import java.awt.Graphics;
import java.net.URL;

import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JPanel;

/**
 * 
 * 自定定带背景图片的Panel
 * 
 * @author Everest
 *
 */
public class JPanelXcu extends JPanel {

	private static final long serialVersionUID = -7844180055896970944L;
	private ImageIcon img; //背景图片
	
	public JPanelXcu() {
		this.img = new ImageIcon(getRes("cn/xcu/img/bgg.jpg"));
	}
	
	public JPanelXcu(ImageIcon imgbg) {
		if(imgbg !=null){			
			this.img = imgbg;
		}else{
			this.img = new ImageIcon(getRes("cn/xcu/img/bgg.jpg"));
		}
	}

	private URL getRes(String str){
	   	 return this.getClass().getClassLoader().getResource(str);
	}
	
	/**
	 * 整张图做背景
	 */
	/*protected void paintComponent(Graphics g) {
		try {
			ImageIcon img = new ImageIcon(getRes("cn/xcu/img/bgg.jpg"));
			g.drawImage(img, 0, 0, 500, 400, null);
		} catch (IOException e) {
			e.printStackTrace();
		}
	}*/

	/**
	 * 小图片填充做背景
	 */
	protected void paintComponent(Graphics g) {
		super.paintComponent(g);
		setOpaque(true);
		Dimension d = getSize();
		for (int x = 0; x < d.width; x += img.getIconWidth()){
			for (int y = 0; y < d.height; y += img.getIconHeight()){
				g.drawImage(img.getImage(), x, y, null, null);
			}
		}
	}
	
	/**
	 * 自测试
	 * @param args
	 */
	public static void main(String[] args) {
		JFrame jf = new JFrame("有背景的panel");
		jf.setSize(500, 400);
		jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

		jf.add(new JPanelXcu());
		jf.setVisible(true);
	}
}