Question

java 键盘事件未响应

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

class Cao extends JFrame
{
private char keychar='A';
public Cao(){
addKeyListener(new KeyAdapter(){
public void KeyPresssed (KeyEvent e){
switch(e.getKeyCode()){
case KeyEvent.VK_UP: break;
case KeyEvent.VK_LEFT: System.out.println("cao") ; break;
case KeyEvent.VK_RIGHT:break;
default:keychar=e.getKeyChar();
}

}
});

}
public static void main(String[] args)
{
Cao k=new Cao();

k.setLocationRelativeTo(null);
k.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
k.setSize(800,850);
k.setVisible(true);
k.setFocusable(true);
}
}
望改动最小，并说明原因。

Answer 1

//你的方法名字写错了 多写了个s
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;

public class Cao extends JFrame {
private char keychar = 'A';

public Cao() {
addKeyListener(new KeyAdapter() {
public void keyPressed(KeyEvent e) {
switch (e.getKeyCode()) {
case KeyEvent.VK_UP:
break;
case KeyEvent.VK_LEFT:
System.out.println("cao");
break;
case KeyEvent.VK_RIGHT:
break;
default:
keychar = e.getKeyChar();
}

}
});

}

public static void main(String[] args) {
Cao k = new Cao();

k.setLocationRelativeTo(null);
k.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
k.setSize(800, 850);
k.setVisible(true);
k.setFocusable(true);
}
}

Answer 2

膜拜下你的方法名和类名。 路过

Answer 3

这个有可能的JPanel的问题，改为Panel试下。