题目要求:用下拉框实现两级联动,第一个为省份,第二个为城市名
代码实现:
import javax.swing.*;
import java.awt.event.*;
public class ItemTest extends JFrame implements ItemListener{
JComboBox province; //一级选项,存放省份
JComboBox city; //二级选项,存放城市名
public ItemTest(){
JLabel label1 = new JLabel("请选择省份:");
label1.setSize(130, 30);
label1.setLocation(20, 60);
this.add(label1);
JLabel label2 = new JLabel("请选择城市:");
label2.setSize(130, 30);
label2.setLocation(20, 130);
this.add(label2);
province = new JComboBox(); //设置省份
String[] pro = getProvinceNames();
for( int i = 0; i < pro.length; i++){
province.addItem(pro[i]);
}
province