程序代码：

import javax.swing.JComboBox;
import javax.swing.JFrame;

public class JComboBoxTest {
   
    private JComboBox comboBox;
    private String[] names;
    private JFrame frame;
   
    public void initUI(){
        names = new String[3];
        names[0] = "QQ号码";
        names[1] = "手机号码";
        names[2] = "小灵通号码";
        comboBox = new JComboBox(names);
        comboBox.setEditable(false);
        frame = new JFrame("Frame");
        frame.getContentPane().add(comboBox);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setVisible(true);   
    }
   
    public static void main(String[] args) {
        new JComboBoxTest().initUI();   
    }
}