java中JComboBox 和JList的使用

1.java中JComboBox 和JList的使用
import java.awt.*;
import javax.swing.*;
public class xialagd extends JFrame
{

/**
* @param args
*/
JPanel mb1,mb2;
JComboBox cb;
JList xl;
JLabel bq1,bq2;
JScrollPane gd;
public static void main(String[] args) {
// TODO Auto-generated method stub
xialagd xd=new xialagd();
}
public xialagd()
{
mb1=new JPanel();
mb2=new JPanel();


String[] xlz={"广东","广西","北京","南方"};
cb=new JComboBox(xlz);
String[] xll={"中学","小学","大学","研究生"};
xl=new JList(xll);
xl.setVisibleRowCount(2);
gd=new JScrollPane(xl);
bq1=new JLabel("籍贯");
bq2=new JLabel("学历");
mb1.add(bq1);mb1.add(cb);
mb2.add(bq2);mb2.add(gd);
this.setLayout(new GridLayout(2,1));
this.add(mb1);
this.add(mb2);
this.setTitle("用户调查");
this.setSize(300,150);
this.setLocation(500,100);
this.setResizable(false);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setVisible(true);
}

}