import java.awt.*;
import java.applet.*;
import java.awt.event.*;
public class KeyEventDemo extends Applet implements KeyListener
{ Button b=new Button("移动");
int x=0,y=0;
public void init()
{ b.addKeyListener(this);
add(b);}
public void KeyTyped(KeyEvent e){}
public void KeyReleased(KeyEvent e){}
public void KeyPressed(KeyEvent e)
{ switch(e.getKeyCode())
{ case KeyEvent.VK_LEFT:
x=x-2;
if (x<=0)
x=0;
b.setLocation(x,y);
break;
case KeyEvent.VK_RIGHT:
x=x+2;
if (x>=400)
x=400;
b.setLocation(x,y);
break;
case KeyEvent.VK_UP:
y=y-2;
if (y<=0)
y=0;
b.setLocation(x,y);
break;
case KeyEvent.VK_DOWN:
y=y+2;
if (y>=400)
y=400;
b.setLocation(x,y);
break;
}
}
}
该段代码编译时出错,提示信息是:KeyEventDemo is not abstruct and does not override abstract method keyReleased(java.awt.event.KeyEvent) in java.awt.event.KeyListener
请高手指教呀!
import java.applet.*;
import java.awt.event.*;
public class KeyEventDemo extends Applet implements KeyListener
{ Button b=new Button("移动");
int x=0,y=0;
public void init()
{ b.addKeyListener(this);
add(b);}
public void KeyTyped(KeyEvent e){}
public void KeyReleased(KeyEvent e){}
public void KeyPressed(KeyEvent e)
{ switch(e.getKeyCode())
{ case KeyEvent.VK_LEFT:
x=x-2;
if (x<=0)
x=0;
b.setLocation(x,y);
break;
case KeyEvent.VK_RIGHT:
x=x+2;
if (x>=400)
x=400;
b.setLocation(x,y);
break;
case KeyEvent.VK_UP:
y=y-2;
if (y<=0)
y=0;
b.setLocation(x,y);
break;
case KeyEvent.VK_DOWN:
y=y+2;
if (y>=400)
y=400;
b.setLocation(x,y);
break;
}
}
}
该段代码编译时出错,提示信息是:KeyEventDemo is not abstruct and does not override abstract method keyReleased(java.awt.event.KeyEvent) in java.awt.event.KeyListener
请高手指教呀!
public void KeyTyped(KeyEvent e)
public void KeyReleased(KeyEvent e)
public void KeyPressed(KeyEvent e) K应该是小写
改为public void keyTyped(KeyEvent e)
public void keyReleased(KeyEvent e)
public void keyPressed(KeyEvent e)