JList和JComboBox都是及其相似的，它们都有一个列表框，只是JComboBox的列表框需要以下拉方式显示出来。
3.设置监听器，监听列表项的变化，JList通过addListSelectionListener完成，JComboBox通过addltemListener完成。
package com.aynu.layout;import javax.swing.*;import javax.swing.border.EtchedBorder;import javax.swing.border.TitledBorder;import javax.swing.event.ListSelectionEvent;import javax.swing.event.ListSelectionListener;import java.awt.*;import java.awt.BorderLayout;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.awt.event.ItemEvent;import java.awt.event.ItemListener;import java.util.List;import java.util.Vector;public class ListTest { JFrame jf = new JFrame("列表框测试"); String[] books ={"三国演义","水浒传","西游记","红楼梦","封神榜"}; //定义 布局选择按钮 所在的面板 JPanel layoutPanel = new JPanel(); ButtonGroup layoutGroup = new ButtonGroup(); //定义 选择模式按钮 所在面板 JPanel selectModePanel = new JPanel(); ButtonGroup selectModeGroup = new ButtonGroup(); JTextArea favorite = new JTextArea(4,40); //用一个字符串数组来创建一个JList对象 JList bookList; JComboBox bookSelector; public void init(){ //组装视图 //组装JList相关内容 bookList = new JList<>(books); addBtn2LayoutPanel("纵向滚动",JList.VERTICAL); addBtn2LayoutPanel("纵向换行",JList.VERTICAL_WRAP); addBtn2LayoutPanel("横向换行",JList.HORIZONTAL_WRAP); addBtn2selectModePanel("无限制",ListSelectionModel.MULTIPLE_INTERVAL_SELECTION); addBtn2selectModePanel("单选",ListSelectionModel.SINGLE_SELECTION); addBtn2selectModePanel("单范围",ListSelectionModel.SINGLE_INTERVAL_SELECTION); //对JList做设置 bookList.setVisibleRowCount(3); bookList.setSelectionInterval(2,4); //处理条目选中事件 bookList.addListSelectionListener(new ListSelectionListener() { @Override public void valueChanged(ListSelectionEvent e) { //获取当前选中的条目 List selectedValuesList = bookList.getSelectedValuesList(); //把当前条目的内容设置到文本域中 favorite.setText(""); for (String str : selectedValuesList) { favorite.append(str+"n"); } } }); Box bookListVBox = Box.createVerticalBox(); bookListVBox.add(new JScrollPane(bookList)); //添加滚动条 bookListVBox.add(layoutPanel); bookListVBox.add(selectModePanel); //组装JComboBox Vector vector = new Vector<>(); List list = List.of("三国演义","水浒传","西游记","红楼梦","封神榜"); vector.addAll(list); bookSelector = new JComboBox<>(vector); //可以直接传数组也可以传vector对象 bookSelector.setEditable(true); bookSelector.setMaximumRowCount(4); bookSelector.addItemListener(new ItemListener() { @Override public void itemStateChanged(ItemEvent e) { //获取当前已选中的条目，把内容设置到文本域中 Object selectedItem = bookSelector.getSelectedItem(); favorite.setText(selectedItem.toString()); } }); //组装顶部的左右两部分 Box topBox = Box.createHorizontalBox(); topBox.add(bookListVBox); JPanel bookSelectPanel = new JPanel(); bookSelectPanel.add(bookSelector); //先将bookSelector放到Panel当中 topBox.add(bookSelectPanel); //将panel添加到topBox当中解决JComboBox组件的拉伸问题 //组装底部 JPanel bottomPanel = new JPanel(); bottomPanel.setLayout(new BorderLayout()); bottomPanel.add(new JLabel("您最喜欢的图书是："),BorderLayout.NORTH); bottomPanel.add(favorite); //组装整体 Box holeBox = Box.createVerticalBox(); holeBox.add(topBox); holeBox.add(bottomPanel); jf.add(holeBox); jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); jf.pack(); jf.setVisible(true); } //封装方法，往layoutPanel中添加单选按钮 public void addBtn2LayoutPanel(String name,int layoutType){ //设置标题边框 layoutPanel.setBorder(new TitledBorder(new EtchedBorder(),"确定选项布局")); //创建单选按钮 JRadioButton button = new JRadioButton(name); layoutPanel.add(button); //让第一个按钮默认选中 if (layoutGroup.getButtonCount()==0){ button.setSelected(true); } layoutGroup.add(button); button.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent e) { bookList.setLayoutOrientation(layoutType); } }); } //封装方法，往selectModePanel中添加按钮 public void addBtn2selectModePanel(String name,int selectMode){ //设置标题边框 selectModePanel.setBorder(new TitledBorder(new EtchedBorder(),"确定选择模式")); //创建单选按钮 JRadioButton button = new JRadioButton(name); selectModePanel.add(button); //让第一个按钮默认选中 if (selectModeGroup.getButtonCount()==0){ button.setSelected(true); } selectModeGroup.add(button); button.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent e) { bookList.setSelectionMode(selectMode); } }); } public static void main(String[] args) { new ListTest().init(); }}
