例如
import java.awt.*;import java.awt.event.*;import java.util.*;import javax.swing.*;public class ComboBoxTwo extends Jframe implements ActionListener, ItemListener { private static final long serialVersionUID = 1L; private JComboBox mainComboBox; private JComboBox subComboBox; private Hashtable<Object, Object> subItems = new Hashtable<Object, Object>(); public ComboBoxTwo() { String[] items = {"Select Item", "Color", "Shape", "Fruit"}; mainComboBox = new JComboBox(items); mainComboBox.addActionListener(this); mainComboBox.addItemListener(this); //prevent action events from being fired when the up/down arrow keys are used //mainComboBox.putClientProperty("JComboBox.isTableCellEditor", Boolean.TRUE); getContentPane().add(mainComboBox, BorderLayout.WEST); subComboBox = new JComboBox();// Create sub combo box with multiple models subComboBox.setPrototypeDisplayValue("XXXXXXXXXX"); // JDK1.4 subComboBox.addItemListener(this); getContentPane().add(subComboBox, BorderLayout.EAST); String[] subItems1 = {"Select Color", "Red", "Blue", "Green"}; subItems.put(items[1], subItems1); String[] subItems2 = {"Select Shape", "Circle", "Square", "Triangle"}; subItems.put(items[2], subItems2); String[] subItems3 = {"Select Fruit", "Apple", "Orange", "Banana"}; subItems.put(items[3], subItems3);// mainComboBox.setSelectedIndex(1); } @Override public void actionPerformed(ActionEvent e) { String item = (String) mainComboBox.getSelectedItem(); Object o = subItems.get(item); if (o == null) { subComboBox.setModel(new DefaultComboBoxModel()); } else { subComboBox.setModel(new DefaultComboBoxModel((String[]) o)); } } @Override public void itemStateChanged(ItemEvent e) { if (e.getStateChange() == ItemEvent.SELECTED) { if (e.getSource() == mainComboBox) { if (mainComboBox.getSelectedIndex() != 0) { FirstDialog firstDialog = new FirstDialog(ComboBoxTwo.this, mainComboBox.getSelectedItem().toString(), "Please wait, Searching for ..... "); } } } } private class FirstDialog extends JDialog { private static final long serialVersionUID = 1L; FirstDialog(final frame parent, String winTitle, String msgString) { super(parent, winTitle); setModalityType(Dialog.ModalityType.APPLICATION_MODAL); JLabel myLabel = new JLabel(msgString); JButton bNext = new JButton("Stop Processes"); add(myLabel, BorderLayout.CENTER); add(bNext, BorderLayout.SOUTH); bNext.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent evt) { setVisible(false); } }); javax.swing.Timer t = new javax.swing.Timer(1000, new ActionListener() { @Override public void actionPerformed(ActionEvent e) { setVisible(false); } }); t.setRepeats(false); t.start(); setLocationRelativeTo(parent); setSize(new Dimension(400, 100)); setVisible(true); } } public static void main(String[] args) { Jframe frame = new ComboBoxTwo(); frame.setDefaultCloseOperation(EXIT_ON_CLOSE); frame.pack(); frame.setLocationRelativeTo(null); frame.setVisible(true); }}
