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【Java】javax.swing.JComboBox 组合框练习 

 1 import java.awt.event.ActionEvent;
 2 import java.awt.event.ActionListener;
 3 import java.awt.event.ItemEvent;
 4 import java.awt.event.ItemListener;
 5 import javax.swing.JComboBox;
 6 import javax.swing.JTextField;
 7 import javax.swing.JFrame;
 8 import java.awt.BorderLayout;
 9 
10 class ExMyFrame65 extends JFrame implements ItemListener, ActionListener {
11     JComboBox comboBox ;
12     JTextField tf ;
13     String[] course = {"语文","数学","物理","英语"};
14     
15     ExMyFrame65(){
16         super.setSize(400,300);
17         super.setTitle("JComBox组合框练习");
18         super.setLayout(new BorderLayout());
19         comboBox = new JComboBox(course);
20         tf = new JTextField("请选择课程");
21         add(comboBox, BorderLayout.NORTH);
22         add(tf, BorderLayout.CENTER);
23         
24         comboBox.setEditable(true); //允许组合框编辑输入
25         
26         comboBox.addItemListener(this); //单选的时候是addItemListener()
27         comboBox.addActionListener(this); //输入选项的时候addActionListener()
28         
29     }
30     
31     @Override
32     public void actionPerformed(ActionEvent arg0) {
33         // TODO Auto-generated method stub
34         if (arg0.getSource() == comboBox) 
35             tf.setText("选择了" + course[comboBox.getSelectedIndex()]);
36     }
37 
38     @Override
39     public void itemStateChanged(ItemEvent arg0) {
40         // TODO Auto-generated method stub
41         if (arg0.getSource() == comboBox)
42             tf.setText("选择了" + course[comboBox.getSelectedIndex()]);
43     }
44 
45 }

 

posted @ 2016-03-12 20:39  uzipi  阅读(427)  评论(0)    收藏  举报