Java 即使我没有';不要松开钥匙
在阅读了一些教程之后,我决定从KeyListeners切换到KeyBinding。我想我已经理解了它们是如何工作的,但是我不明白为什么这个小程序会检测到密钥释放,即使我不释放密钥。编辑:我在Linux机器上Java 即使我没有';不要松开钥匙,java,swing,key-bindings,keystrokes,Java,Swing,Key Bindings,Keystrokes,在阅读了一些教程之后,我决定从KeyListeners切换到KeyBinding。我想我已经理解了它们是如何工作的,但是我不明白为什么这个小程序会检测到密钥释放,即使我不释放密钥。编辑:我在Linux机器上 //KeyBindingsTest.java import javax.swing.*; import java.awt.event.*; public class KeyBindingsTest{ private JFrame w = new JFrame();
//KeyBindingsTest.java
import javax.swing.*;
import java.awt.event.*;
public class KeyBindingsTest{
private JFrame w = new JFrame();
private JComponent j = new JPanel();
public KeyBindingsTest(){
w.setSize(400,400);
w.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
w.setVisible(true);
setKeyBindings();
w.add(j);
}
public static void main(String[] args){
new KeyBindingsTest();
}
private void setKeyBindings(){
InputMap im = j.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW);
ActionMap am = j.getActionMap();
im.put(KeyStroke.getKeyStroke(KeyEvent.VK_1, 0, false), "pressed");
im.put(KeyStroke.getKeyStroke(KeyEvent.VK_1, 0, true), "released");
am.put("pressed", new AbstractAction() {
@Override
public void actionPerformed(ActionEvent e) {
System.out.println("Pressed");
}
});
am.put("released", new AbstractAction() {
@Override
public void actionPerformed(ActionEvent e) {
System.out.println("Released");
}
});
j.setFocusable(true);
j.requestFocusInWindow();
}
}
如果我按下“1”键,我希望程序能够连续打印:
Pressed
Pressed
Pressed...
但它显示:
Pressed
Released
Pressed
Released...
我一定错过了一些东西,一些非常简单的东西
编辑:现在我想出了一个肮脏的解决办法,但我仍然希望有人能解释如何以适当的方式解决这个问题。这是:
// the beginning of the file should stay the same
private void setKeyBindings(){
InputMap im = getInputMap(JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT);
ActionMap am = getActionMap();
im.put(KeyStroke.getKeyStroke(KeyEvent.VK_1, 0, false), "pressed");
im.put(KeyStroke.getKeyStroke(KeyEvent.VK_1, 0, true), "released");
class MyAction extends AbstractAction{
private String s;
public MyAction(String s){
this.s = s;
}
@Override
public void actionPerformed(ActionEvent e) {
if(s.equals("pressed"))setKeyPressed();
else if(s.equals("released"))tryToSetKeyReleased();
}
}
am.put("pressed", new MyAction("pressed"));
am.put("released", new MyAction("released"));
setFocusable(true);
requestFocusInWindow();
}
public boolean pressed = false;
public void setKeyPressed(){System.out.println("key pressed");pressed =true;}
public void setKeyReleased(){System.out.println("key released");pressed = false;}
public void tryToSetKeyReleased(){
pressed = false;
(new Thread(
new Runnable(){
@Override
public void run() {
try{Thread.sleep(5);}
catch(Exception e){;}
if(pressed==false)setKeyReleased();
}
}
)).start();
}
这与操作系统有关。例如,如果您连续按记事本中的某个字符,它将连续打印该字符。因此,它不断地发送新闻发布信号 这是KeyEvents的正确输出,基于本机OSthen的设置。我如何区分程序中按下的键和释放的键?谢谢。但是,我如何分别检测按键和释放?因为使用KeyListener没有歧义,所以只有在实际释放密钥时才会触发密钥释放事件。Windows在结束时提供多个按键按下,但只有一个按键释放事件。检查这条线:该死,那只虫子已经15岁了(这怎么可能?这也很奇怪,因为在那个线程中,他们在使用KeyListener时遇到了这个问题,而我在使用它们时从来没有遇到过这个问题。建议的解决方法修复了KeyListener,但我会尝试将其适应KeyBinding。