Java 键盘监听事件的疑惑

[zjjh8877227]

键盘的监听事件应该是加在Frame上面还算应该加在Panel或者其他的组件上面呢？如果有多个组件都需要监听，那么它们之间也无法区分啊，怎么办？

KeyHandler kyListener = new KeyHandler();
	    scandocDRPane.addKeyListener(kyListener);

class KeyHandler implements KeyListener{
	
	public void keyPressed(KeyEvent e) {
		System.out.println("1");	
		 if(e.getKeyCode() == KeyEvent.VK_K){//
				System.out.println("kkkk");	
				}
	}
	public void keyReleased(KeyEvent e) {
		System.out.println("2");	
	}
	public void keyTyped(KeyEvent e) {
		System.out.println("3");	
	}
	
    } 

这段代码无任何反应，不知道哪里出问题了，各位大大帮忙看看，或者是不是什么焦点的问题？

[prince_java]

哪个组建需要就建立在谁上，如果多个组件用的是同一个监听事件，就写个类单独存放

[zjjh8877227]

[Quote=引用 1 楼 closewbq 的回复:]

看看例子！
Java code

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class TestEvent extends JFrame {
private static final long serialVersionUID = 1L;
public TestEvent(……
[/Quote]
换成你这样子的也不行

[closewbq]

看看例子！

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class TestEvent extends JFrame {
	private static final long serialVersionUID = 1L;
	public TestEvent() {
		setSize(400, 300);
		P p1 = new P();
		System.out.println(p1.isFocusable());
		p1.setFocusable(true);
		p1.setBackground(Color.red);
		this.getContentPane().add(BorderLayout.NORTH, p1);
		P p2 = new P();
		p2.setBackground(Color.green);
		this.getContentPane().add(BorderLayout.SOUTH, p2);
		setVisible(true);
		this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	}
	public static void main(String[] args) {
		new TestEvent();
	}
}
class P extends JPanel {
	private static final long serialVersionUID = 1L;
	public P() {
		addKeyListener(new Listener());
		this.addMouseListener(new MouseAdapter() {
			public void mouseClicked(MouseEvent e) {
				System.out.println(e);
			}
		});
	}
}
class Listener implements KeyListener {
	public void keyPressed(KeyEvent e) {
		System.out.println("---" + e);
	}
	public void keyReleased(KeyEvent e) {
	}
	public void keyTyped(KeyEvent e) {
	}
}