JAVA Swing 图片按钮布局

package elts.ui;

import javax.swing.*;
import javax.swing.border.*;
import java.awt.*;

public class MenuFrame extends JFrame {
  public MenuFrame(){
  init();
  }
  private void init(){
  setTitle("在线评测");
  setSize(600,400);
  setResizable(false);
  setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  setLocationRelativeTo(null);
  //添加主面板
  setContentPane(createContentPane());
  }
  //创建主面板  
  private JPanel createContentPane(){
  JPanel p=new JPanel(new BorderLayout());
  p.add(BorderLayout.NORTH,
     createImagePane());
  p.add(BorderLayout.CENTER,
    createCenterPane());
  p.add(BorderLayout.SOUTH,
  new JLabel("版权所有 盗版必究",JLabel.RIGHT));
  return p;
  }
//创建中间部分的面板
private JPanel createCenterPane() {
JPanel p=new JPanel(new BorderLayout());
info=new JLabel("欢迎***参加考试",JLabel.CENTER);
p.add(BorderLayout.NORTH,info);
p.add(createMenuPane());
return p;
}
//创建菜单所在的窗格
private JPanel createMenuPane() {
JPanel p=new JPanel();
JButton start=createImageButton("开始","exam.png");
p.add(start);
JButton result=createImageButton("分数","result.png");
p.add(result);
JButton message=createImageButton("规则","message.png");
p.add(message);
JButton exit=createImageButton("离开","exit.png");
p.add(exit);
return p;

}
//辅助方法，用于创建图像按钮
private JButton createImageButton(
     String text,String image){
   ImageIcon icon=new ImageIcon(
   getClass().getResource(image));
   JButton btn=new JButton(text,icon);
   btn.setHorizontalTextPosition(
             JButton.CENTER);
   btn.setVerticalTextPosition(
             JButton.BOTTOM);
   return btn;
}
private JPanel createImagePane() {
JPanel p=new JPanel();
ImageIcon icon2=new ImageIcon(
getClass().getResource("title.png"));
p.add(new JLabel(icon2));
return p;
}
//定义私有属性
private JLabel info;
//main方法
public static void main(String[] args) {
MenuFrame menu=new MenuFrame();
menu.setVisible(true);
}
}