开发者

Java Swing KeyStrokes: how to make CTRL-modifier work

开发者 https://www.devze.com 2022-12-22 18:09 出处:网络
In the following program, why does hitting the a key print \"hello, world\" while hitting CTRL+a doesn\'t?

In the following program, why does hitting the a key print "hello, world" while hitting CTRL+a doesn't?

import java.awt.event.*;
import javax.swing.*;

public class KeyStrokeTest {
    public static void main(String[] args) {
        JPanel panel = new JPanel();

        /* add a new action named "foo" to the panel's action map */
        panel.getActionMap().put("foo", new AbstractAction() {
                public void actionPerformed(ActionEvent e) {
                    System.out.println("hello, world");
                }
            });

        /* connect two keystrokes with the newly created "foo" action:
           - a
           - CTRL-a
        */
        InputMap inputMap = panel.getInputM开发者_JS百科ap();
        inputMap.put(KeyStroke.getKeyStroke(Character.valueOf('a'), 0), "foo");
        inputMap.put(KeyStroke.getKeyStroke(Character.valueOf('a'), InputEvent.CTRL_DOWN_MASK), "foo");

        /* display the panel in a frame */
        JFrame frame = new JFrame();
        frame.getContentPane().add(panel);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(400, 400);
        frame.setVisible(true);
    }
}

How could I fix it that CTRL+a works as well?


I find it easier to use:

KeyStroke a = KeyStroke.getKeyStroke("A");
KeyStroke controlA = KeyStroke.getKeyStroke("control A");

or:

KeyStroke controlA = KeyStroke.getKeyStroke(KeyEvent.VK_A, InputEvent.CTRL_MASK);


Dude, use this

inputMap.put(KeyStroke.getKeyStroke(KeyEvent.VK_A, InputEvent.CTRL_MASK), "foo");


Yep, the above code will work.

Big picture - Ctrl+a and a are read as different keystrokes the same as a and b would be different.

0

精彩评论

暂无评论...
验证码 换一张
取 消

关注公众号