setMnemonic()并通过按键调用一个方法

Question

我必须手动运行一个方法当按下键Alt+H

if("The key pressed==(Alt+H)"){
    callMethod();
}
public void callMethod(){
    //Some codes here
}

如何在Java中实现。请给我一个简单的方法。

Answer 1

值得在这里阅读Oracle教程-启用键盘操作，其中详细解释了示例。

阅读更多关于Oracle教程-如何使用键绑定

直接从上面的教程中的一些例子:

//Setting the mnemonic when constructing a menu item:
menuItem = new JMenuItem("A text-only menu item",
                     KeyEvent.VK_H);
//Setting the mnemonic after creation time:
menuItem.setMnemonic(KeyEvent.VK_H);
//Setting the accelerator:
menuItem.setAccelerator(KeyStroke.getKeyStroke(
    KeyEvent.VK_H, ActionEvent.ALT_MASK));

---

阅读更多在这里Oracle教程-如何使用按钮，复选框和单选按钮

示例代码:(Alt-H将点击中间按钮)

JButton b2 = new JButton("Middle button", middleButtonIcon);
b2.setMnemonic(KeyEvent.VK_H);

Answer 2

如果使用菜单，则可以使用setMnemonic()，请参见如何使用菜单的示例。另一个选择是使用键绑定。例如:

import java.awt.event.*;
import javax.swing.*;
public class TestKeys {
    private static void createAndShowGUI() {
        final JFrame frame = new JFrame("Keys");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        KeyStroke escapeKeyStroke = KeyStroke.getKeyStroke(KeyEvent.VK_H, InputEvent.ALT_MASK);
        Action testAction = new AbstractAction() {
            public void actionPerformed(ActionEvent e) {
                 JOptionPane.showMessageDialog(frame, "Alt-H pressed");
            }
        };
        frame.getRootPane().getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(escapeKeyStroke, "TestAction");
        frame.getRootPane().getActionMap().put("TestAction", testAction);       
        JLabel label = new JLabel("Hit Alt-H");
        label.setBorder(BorderFactory.createEmptyBorder(20, 20, 20, 20));
        frame.add(label);
        frame.setLocationByPlatform(true);
        frame.pack();
        frame.setVisible(true);
    }
    public static void main(String args[]) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
            }
        });
    }
}

Answer 3

最好的方法是使用setmnemon()，因为它是最简单的。

查看这篇文章获取更多信息http://www.herongyang.com/Swing/JMenuBar-Set-Keyboard-Mnemonics-on-Menu-Items.html

private JMenu getColorMenu() {
  JMenu myMenu = new JMenu("Color");
  ButtonGroup myGroup = new ButtonGroup();
  JRadioButtonMenuItem myItem = new JRadioButtonMenuItem("Red");
  myItem.setSelected(true);
  myItem.setMnemonic(KeyEvent.VK_R);
  myItem.addActionListener(this);
  myItem.addMenuKeyListener(this);
  myGroup.add(myItem);
  myMenu.add(myItem);
  myItem = new JRadioButtonMenuItem("Green");
  myItem.setMnemonic(KeyEvent.VK_G);
  myItem.addActionListener(this);
  myItem.addMenuKeyListener(this);
  myGroup.add(myItem);
  myMenu.add(myItem);
  myItem = new JRadioButtonMenuItem("Blue");
  myItem.setMnemonic(KeyEvent.VK_B);
  myItem.addActionListener(this);
  myItem.addMenuKeyListener(this);
  myGroup.add(myItem);
  myMenu.add(myItem);
  return myMenu;