jcomboboxdemo.java

学习参考,java基本语法练习,包括一些常用的技巧

//JComboBox组件演示
import javax.swing.*;
//import javax.swing.event.*;
import java.awt.*;
import java.awt.event.*;

public class JComboBoxDemo extends JFrame implements ActionListener
{
	JPanel pnlMain;
	DefaultListModel dlmName;
	JComboBox cmbName;
	JLabel lblCombo,lblInfo,lblSelect;
	String  strName[]={"刘志成","赵爱云","张自良","邱中华","王咏梅"};
	public JComboBoxDemo()
	{
		super("JComboBox组件演示");
		pnlMain=new JPanel(null);
		setContentPane(pnlMain);
		cmbName=new JComboBox(strName);
		cmbName.setBounds(110,10,80,30);
		//设置组合框可进行编辑
		cmbName.setEditable(true);
		cmbName.addActionListener(this);
		//如果使用了该语句
		//lblSelect对象必须在cmbName对象之前产生,否则ActionPermed方法会产生异常
		//cmbName.setSelectedIndex(0);
		lblCombo=new JLabel("请选择姓名:");
		lblCombo.setBounds(5,10,80,30);
		lblInfo=new JLabel("您选择的是:");
		lblInfo.setBounds(5,50,80,30);
		lblSelect=new JLabel("尚未选择");
		lblSelect.setBounds(110,50,80,30);
		lblSelect.setForeground(Color.RED);
		pnlMain.add(lblCombo);
		pnlMain.add(cmbName);
		pnlMain.add(lblInfo);
		pnlMain.add(lblSelect);
		setSize(250,150);
		setVisible(true);
	}
 	public void actionPerformed(ActionEvent ae) 
 	{
 			lblSelect.setText((String)cmbName.getSelectedItem());
 	}
 	public static void main(String args[])
	{
		new JComboBoxDemo();
	}
}