Tips:
（1）JList不能自动滚动，要想为列表框加上滚动条，必须将JList插入到一个JScrollPane中，然后将JScollPane而不是JList，插入到外围JPanel上
（2）ListSelectionListener
public void valueChanged(ListSelectionEvent event)
在用户选择了若干个选项的同时，将产生一系统列表选择事件。假如用户在一个新选项上单击，当鼠标按下的时候，就会有一个事件报告选项的改变。这是一种过渡型事件。在调用event.isAdjusting()时，如果该选择仍未最终结束则返回true.然后，当松开鼠标时，就产生另一事件，此时isAdjusting返回false.如果对过渡事件不感兴趣，那么可以等待isAdjusting调用返回false的事件。
不过，如果希望只要点击鼠标就给用户一个即时反馈，那么就需要处理所有的事件。
（3）JList不响应鼠标的双击事件。正如Swing设计者所构想的那样，使用列表选择一个选项，然后点击某个按钮执行某个动作。
如果想让JList对双击事件进行响应，必须对JList添加一个鼠标监听器，然后按照下面这样捕获鼠标事件：
eg:
wordList.addMouseListener(new MouseListener() { @Override public void mouseReleased(MouseEvent e) { // TODO Auto-generated method stub } @Override public void mousePressed(MouseEvent e) { } @Override public void mouseExited(MouseEvent e) { } @Override public void mouseEntered(MouseEvent e) { } @Override public void mouseClicked(MouseEvent e) { if (e.getClickCount()==2) { JList source=(JList) e.getSource(); Object[] selection=source.getSelectedValues(); doAction(selection); } } });
package swing.jlist; import java.awt.BorderLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.ButtonGroup; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JList; import javax.swing.JPanel; import javax.swing.JRadioButton; import javax.swing.JScrollPane; import javax.swing.event.ListSelectionEvent; import javax.swing.event.ListSelectionListener; /*2015-7-8*/ public class JListTest { public static void main(String[] args) { ListFrame frame = new ListFrame(); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setVisible(true); frame.setLocationRelativeTo(null); } } class ListFrame extends JFrame { private static final long serialVersionUID = 1L; private static final int DEFAULT_WIDTH = 400; private static final int DEFAULT_HEIGHT = 300; private JPanel listPanel; private JList wordList; private JLabel label; private JPanel buttonPanel; private ButtonGroup group; private String prefix = "The "; private String suffix = "fox jumps over the lazy dog."; public ListFrame() { setTitle("ListTest"); setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT); String[] words = { "quick", "brown", "hungry", "wild", "silent", "huge", "private", "abstract", "static", "final" }; wordList = new JList(words); wordList.setVisibleRowCount(4); JScrollPane scrollPane = new JScrollPane(wordList); listPanel = new JPanel(); listPanel.add(scrollPane); wordList.addListSelectionListener(new ListSelectionListener() { @Override public void valueChanged(ListSelectionEvent e) { Object[] values = wordList.getSelectedValues(); StringBuilder text = new StringBuilder(prefix); for (int i = 0; i < values.length; i++) { String word = (String) values[i]; text.append(word); text.append(" "); } text.append(suffix); label.setText(text.toString()); } }); buttonPanel = new JPanel(); group = new ButtonGroup(); makeButton("Vertical", JList.VERTICAL); makeButton("VERTICAL_WRAP", JList.VERTICAL_WRAP); makeButton("HORIZONTAL_WRAP", JList.HORIZONTAL_WRAP); add(listPanel, BorderLayout.NORTH); label = new JLabel(prefix + suffix); add(label, BorderLayout.CENTER); add(buttonPanel, BorderLayout.SOUTH); } private void makeButton(String label, final int orientation) { JRadioButton button = new JRadioButton(label); buttonPanel.add(button); if (group.getButtonCount() == 0) { button.setSelected(true); } group.add(button); button.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent e) { wordList.setLayoutOrientation(orientation); listPanel.revalidate(); } }); } }
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