menuItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_1,ActionEvent.ALT_MASK));
menuItem.getAccessibleContext().setAccessibleDescription("This doesn't really do anything!");
这两句话分别是用来做什么的?
menuItem.getAccessibleContext().setAccessibleDescription("This doesn't really do anything!");
这两句话分别是用来做什么的?
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;public class MenuTest
{
public static void main(String[] args)
{
MenuFrame frame = new MenuFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.show();
}
}/**
A frame with a sample menu bar.
*/
class MenuFrame extends JFrame
{
public MenuFrame()
{
setTitle("MenuTest");
setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT); JMenu fileMenu = new JMenu("File");
JMenuItem newItem = fileMenu.add(new TestAction("New")); // demonstrate accelerators JMenuItem openItem = fileMenu.add(new TestAction("Open"));
openItem.setAccelerator(KeyStroke.getKeyStroke(
KeyEvent.VK_O, InputEvent.CTRL_MASK)); fileMenu.addSeparator();
saveAction = new TestAction("Save");
JMenuItem saveItem = fileMenu.add(saveAction);
saveItem.setAccelerator(KeyStroke.getKeyStroke(
KeyEvent.VK_S, InputEvent.CTRL_MASK)); saveAsAction = new TestAction("Save As");
JMenuItem saveAsItem = fileMenu.add(saveAsAction);
fileMenu.addSeparator(); fileMenu.add(new
AbstractAction("Exit")
{
public void actionPerformed(ActionEvent event)
{
System.exit(0);
}
}); // demonstrate check box and radio button menus readonlyItem = new JCheckBoxMenuItem("Read-only");
readonlyItem.addActionListener(new
ActionListener()
{
public void actionPerformed(ActionEvent event)
{
boolean saveOk = !readonlyItem.isSelected();
saveAction.setEnabled(saveOk);
saveAsAction.setEnabled(saveOk);
}
}); ButtonGroup group = new ButtonGroup(); JRadioButtonMenuItem insertItem
= new JRadioButtonMenuItem("Insert");
insertItem.setSelected(true);
JRadioButtonMenuItem overtypeItem
= new JRadioButtonMenuItem("Overtype"); group.add(insertItem);
group.add(overtypeItem); // demonstrate icons Action cutAction = new TestAction("Cut");
cutAction.putValue(Action.SMALL_ICON,
new ImageIcon("cut.gif"));
Action copyAction = new TestAction("Copy");
copyAction.putValue(Action.SMALL_ICON,
new ImageIcon("copy.gif"));
Action pasteAction = new TestAction("Paste");
pasteAction.putValue(Action.SMALL_ICON,
new ImageIcon("paste.gif")); JMenu editMenu = new JMenu("Edit");
editMenu.add(cutAction);
editMenu.add(copyAction);
editMenu.add(pasteAction); // demonstrate nested menus JMenu optionMenu = new JMenu("Options"); optionMenu.add(readonlyItem);
optionMenu.addSeparator();
optionMenu.add(insertItem);
optionMenu.add(overtypeItem); editMenu.addSeparator();
editMenu.add(optionMenu); // demonstrate mnemonics JMenu helpMenu = new JMenu("Help");
helpMenu.setMnemonic('H'); JMenuItem indexItem = new JMenuItem("Index");
indexItem.setMnemonic('I');
helpMenu.add(indexItem); // you can also add the mnemonic key to an action
Action aboutAction = new TestAction("About");
aboutAction.putValue(Action.MNEMONIC_KEY,
new Integer('A'));
helpMenu.add(aboutAction); // add all top-level menus to menu bar JMenuBar menuBar = new JMenuBar();
setJMenuBar(menuBar); menuBar.add(fileMenu);
menuBar.add(editMenu);
menuBar.add(helpMenu); // demonstrate pop-ups popup = new JPopupMenu();
popup.add(cutAction);
popup.add(copyAction);
popup.add(pasteAction); getContentPane().addMouseListener(new
MouseAdapter()
{
public void mousePressed(MouseEvent event)
{
if (event.isPopupTrigger())
popup.show(event.getComponent(),
event.getX(), event.getY());
} public void mouseReleased(MouseEvent event)
{
if (event.isPopupTrigger())
popup.show(event.getComponent(),
event.getX(), event.getY());
}
});
} public static final int DEFAULT_WIDTH = 300;
public static final int DEFAULT_HEIGHT = 200; private Action saveAction;
private Action saveAsAction;
private JCheckBoxMenuItem readonlyItem;
private JPopupMenu popup;
}/**
A sample action that prints the action name to System.out
*/
class TestAction extends AbstractAction
{
public TestAction(String name) { super(name); }
public void actionPerformed(ActionEvent event)
{
System.out.println(getValue(Action.NAME)
+ " selected.");
}
}
说不如做..你看了这个例子全部明白..