Java JComboBox

1 Java JComboBox的介绍

Choice类的对象用于显示选项的弹出菜单。用户选择的选项显示在菜单顶部。它继承了JComponent类。

2 Java JComboBox的声明

我们来看一下javax.swing.JComboBox类的声明。

public class JComboBox extends JComponent implements ItemSelectable, ListDataListener, ActionListener, Accessible  

3 Java JComboBox的构造方法

4 Java JComboBox的方法

5 Java JComboBox的案例1

package com.yiidian;

/**
 * 一点教程网： http://www.yiidian.com
 */

import javax.swing.*;

public class ComboBoxExample {    
    JFrame f;
    ComboBoxExample(){
        f=new JFrame("JComboBox案例");
        String country[]={"India","Aus","U.S.A","England","Newzealand"};
        JComboBox cb=new JComboBox(country);
        cb.setBounds(50, 50,90,20);
        f.add(cb);
        f.setLayout(null);
        f.setSize(400,500);
        f.setVisible(true);
    }
    public static void main(String[] args) {
        new ComboBoxExample();
    }
}

输出结果为：

6 Java JComboBox的案例2

package com.yiidian;

/**
 * 一点教程网： http://www.yiidian.com
 */

import javax.swing.*;
import java.awt.event.*;
public class ComboBoxExample {
    JFrame f;
    ComboBoxExample(){
        f=new JFrame("JComboBox案例");
        final JLabel label = new JLabel();
        label.setHorizontalAlignment(JLabel.CENTER);
        label.setSize(400,100);
        JButton b=new JButton("Show");
        b.setBounds(200,100,75,20);
        String languages[]={"C","C++","C#","Java","PHP"};
        final JComboBox cb=new JComboBox(languages);
        cb.setBounds(50, 100,90,20);
        f.add(cb); f.add(label); f.add(b);
        f.setLayout(null);
        f.setSize(350,350);
        f.setVisible(true);
        b.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                String data = "你选择的编程语言是: "
                        + cb.getItemAt(cb.getSelectedIndex());
                label.setText(data);
            }
        });
    }
    public static void main(String[] args) {
        new ComboBoxExample();
    }
}

输出结果为：