java - 如何在 Java Swing 中为特殊键定义快捷方式，例如德语变音键 Ä?

Question

如何为顶级特殊键(如德语变音键 Ä)定义键盘快捷键？我找到了一种映射用于默认美国布局键的 unicode 字母的方法，请参阅 here .但是德语变音键 Ä 的关键事件是:

java.awt.event.KeyEvent[KEY_PRESSED,keyCode=0,keyText=Unknown keyCode: 0x0,keyChar='ä',keyLocation=KEY_LOCATION_STANDARD,rawCode=222,primaryLevelUnicode=228,scancode=40] on frame0 

想法是注册一个键盘 Action :

import java.awt.Dimension;
import java.awt.event.ActionEvent;

import javax.swing.AbstractAction;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.KeyStroke;
import javax.swing.SwingUtilities;


public class KeyStrokeForGermanUmlaut {

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                JFrame frame = new JFrame();
                frame.setPreferredSize(new Dimension(600, 400));
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

                JPanel panel = new JPanel();
                final JLabel label = new JLabel("Text shall change with shortcut");
                panel.add(label);
                panel.registerKeyboardAction(new AbstractAction() {
                    @Override
                    public void actionPerformed(ActionEvent event) {
                        label.setText("It is working!!!");
                    }
                }, KeyStroke.getKeyStroke("control typed Ä"), JComponent.WHEN_IN_FOCUSED_WINDOW);

                frame.getContentPane().add(panel);
                frame.pack();
                frame.setVisible(true);
            }
        });
    }
}

Answer 1

• 你可以用 JLabel 变戏法，KeyEvents 没有任何反应

• 应该以将焦点移动到 JFrames ContentPane 为起点(可以用作 JPanel，但与普通 JPanel - FlowLayout 相比具有 BorderLayout)

-

import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import javax.swing.AbstractAction;
import javax.swing.Action;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.KeyStroke;
import javax.swing.SwingUtilities;

public class KeyStrokeForGermanUmlaut {

    private JFrame frame = new JFrame();
    private JLabel label = new JLabel("Text shall change with shortcut");

    public KeyStrokeForGermanUmlaut() {
        frame.getRootPane().getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(
                KeyStroke.getKeyStroke(KeyEvent.VK_A, KeyEvent.CTRL_MASK), "CTRL + A");
        frame.getRootPane().getActionMap().put("CTRL + A", updateCol());
        frame.setPreferredSize(new Dimension(600, 100));
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.add(label);
        frame.pack();
        frame.setLocation(150, 150);
        frame.setVisible(true);
    }

    private Action updateCol() {
        return new AbstractAction("Hello World") {
            private static final long serialVersionUID = 1L;

            @Override
            public void actionPerformed(ActionEvent e) {
                label.setText(label.getText() + " presses");
            }
        };
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                new KeyStrokeForGermanUmlaut();
            }
        });
    }
}

.

.

---

EDIT 请参阅 API 中的说明 getKeyStroke/ v.s. getKeyStrokeForEvent

那么结果可能是(何时以及如何对这两个字符使用大写形式的修饰符 SHIFT(ä 和 ú)有点丢失，也许有人会帮助我们处理这些 KeyEvents)

来自

import java.awt.Dimension;
import java.awt.event.ActionEvent;
import javax.swing.AbstractAction;
import javax.swing.Action;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.KeyStroke;
import javax.swing.SwingUtilities;

public class KeyStrokeForGermanUmlaut {

    private JFrame frame = new JFrame();
    private JLabel label = new JLabel("Text shall change with shortcut");

    public KeyStrokeForGermanUmlaut() {
        frame.getRootPane().getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(
                KeyStroke.getKeyStroke("typed ä"), "typed ä");
        frame.getRootPane().getActionMap().put("typed ä", updateCol());
        frame.getRootPane().getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(
                KeyStroke.getKeyStroke("typed ú"), "typed ú");
        frame.getRootPane().getActionMap().put("typed ú", updateCol1());
        frame.setPreferredSize(new Dimension(600, 100));
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.add(label);
        frame.pack();
        frame.setLocation(150, 150);
        frame.setVisible(true);
    }

    private Action updateCol() {
        return new AbstractAction("Hello World") {
            private static final long serialVersionUID = 1L;

            @Override
            public void actionPerformed(ActionEvent e) {
                label.setText(label.getText() + " presses - ä");
            }
        };
    }

    private Action updateCol1() {
        return new AbstractAction("Hello World") {
            private static final long serialVersionUID = 1L;

            @Override
            public void actionPerformed(ActionEvent e) {
                label.setText(label.getText() + " presses - ú");
            }
        };
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                new KeyStrokeForGermanUmlaut();
            }
        });
    }
}