java UI之下拉列表与滚动条

package com.SwingIn51;
import javax.swing.*;
import java.awt.*;
public class JComboxAndJList extends JFrame{
	JPanel panel1,panel2;
	JLabel label1,label2;
	JComboBox box;//设置下拉列表
	JList list;//
	JScrollPane sp;//设置滚动条
	
	JComboxAndJList(){
		panel1=new JPanel();
		panel2=new JPanel();
		label1=new JLabel("籍贯");
		label2=new JLabel("学历");
		String [] address= {"北京","天津","上海","福建","广州"};//用个数组
		box=new JComboBox(address);//把选项添加进下拉列表

		
		String []education= {"高中","大专","本科","硕士","博士"};
		list=new JList(education);
		list.setVisibleRowCount(3);//设置单选款默认显示三个
		sp=new JScrollPane(list);//将列表添加进滚动条
		
		this.setLayout(new GridLayout(2,1));
		panel1.add(label1);
	    panel1.add(box);
		panel2.add(label2);

		//panel2.add(list);
		panel2.add(sp);//直接添加这个，这与前面的buttongroup不同
		
		this.add(panel1);
		this.add(panel2);
		this.setTitle("用户调查");
		this.setSize(400, 190);
		this.setLocation(300, 200);
		this.setResizable(false);
		this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		this.setVisible(true);
		
		
		
	}
	public static void main(String[] args) {
		JComboxAndJList b=new JComboxAndJList();
	}
	


}