小游戏

最近在写Swing的程序，对怎么在在Jpanel上放置背景网上大多数是在上面加个JLabel，然后设置JLAbel的Icon！但这样做后，JPanel上加其它组件就不好处理了!于是想到继承JPanel然后再重写paintComponent(Graphics g)和paintChildren(Graphics g)这两个方法,这样就保证了JPanel，最初的状态，想怎么处理其它组件都行了;以下是源代码:

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;

import javax.swing.ImageIcon;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.ScrollPaneConstants;

public class BackGroundPane extends JPanel {
 private ImageIcon imageIcon;
 
 public ImageIcon getImageIcon() {
  return imageIcon;
 }

 public void setImageIcon(ImageIcon imageIcon) {//设置图片
  this.imageIcon = imageIcon;
 }

 public BackGroundPane() {
  super();
  this.setOpaque(false);
 }

 protected void paintChildren(Graphics g) {//重绘JPanel下的Components
  super.paintChildren(g);
  for(int i =0;i<this.getComponents().length;i++){
   this.getComponent(i).repaint();
  }
  g.dispose();
 }

 protected void paintComponent(Graphics g) {
  Graphics2D g2D = (Graphics2D)g;
  super.paintComponent(g2D);

if(imageIcon!=null){//绘制背景
   g2D.drawImage(imageIcon.getImage(), 0, 0,this.getWidth(),this.getHeight(),this);

}
  g2D.dispose();
 }
}

在调用的时候只要新建一个对象，然后再调用setImageIcon(ImageIcon imageIcon)方法就是可以绘制背景了，如果没有背景也可以当JPanel！！