奇怪，为何我在文本框添加的键盘适配器不起作用？其他适配器都可以！

import java.awt.*;
import java.awt.event.*;
class MouseAndKey
{
private Frame frame;
private Button but;
private TextField tf;
MouseAndKey(){
init();
}
public void init(){//初始化对象
frame=new Frame("javatest.exe");
frame.setBounds(400,400,500,400);
frame.setLayout(new FlowLayout());
but=new Button("测试按钮");
tf=new TextField(10);
frame.add(but);
frame.add(tf);
frame.setVisible(true);
myEvent();

}
public void myEvent(){
    tf.addKeyListener(new KeyAdapter(){//给文本框加入键盘监视器
        public void KeyPressed(KeyEvent e){
            int code=e.getKeyCode();
            if(!(code>=KeyEvent.VK_0 && code<=KeyEvent.VK_9)){
                System.out.println(KeyEvent.getKeyText(code)+":非法字符");
                e.consume();
            }
        }
    });
    frame.addWindowListener(new WindowAdapter(){//给窗体加入窗体适配器
        public void windowClosing(WindowEvent e){
            System.out.println("窗体动作，关闭窗体");
            System.exit(0);
        }   
    });
    but.addActionListener(new ActionListener(){//给按钮加入活动监视器
        public void actionPerformed(ActionEvent e){
            System.out.println("按钮动作！");

        }
    });
    but.addMouseListener(new MouseAdapter(){//给按钮加入鼠标适配器
        public void mouseClicked(MouseEvent me){
            if(me.getClickCount()==2){
                System.out.println("双标事件，双击两次退出窗口");
                System.exit(0);
            }
            System.out.println("鼠标事件，单击了一次");
        }
        public void mouseEntered(MouseEvent me){
            System.out.println("鼠标事件，鼠标进入");
        }
    });
    but.addKeyListener(new KeyAdapter(){//给按钮加入键盘适配器
        public void keyPressed(KeyEvent e){
            System.out.println("键盘动作，键盘按下");
        }
    });
}
public static void main(String[] args) 
{
    new MouseAndKey();
    System.out.println("Hello World!");
}

}

 //账号文本框监听键盘事件
        zhangHao.addKeyListener(new KeyAdapter(){
            public void keyPressed(KeyEvent e){
                if(e.getKeyChar()==KeyEvent.VK_ENTER){
                    dL.doClick();
                }
            }
        });

        //密码文本框监听键盘事件
        pass.addKeyListener(new KeyAdapter(){
            public void keyPressed(KeyEvent e){
                if(e.getKeyChar()==KeyEvent.VK_ENTER){
                    dL.doClick();
                }
            }
        });