keydraw.java

Java课程中所有的可运行程序 全部都是java课程中所涉及到的源码

import java.awt.*;
import java.awt.event.*;

public class keydraw extends Frame implements KeyListener{

   public Label l1=new Label(" ");
  int xpos=100,ypos=100;

    public  keydraw(){
        super("key event");
        setLayout(new FlowLayout());

         addKeyListener(this);
         add(l1);

      this.setSize(400,300);
        this.setVisible(true);
    }

public static void main(String[] args){
  keydraw nowframe=new keydraw();
  nowframe.addWindowListener(new WindowAdapter(){
   public void windowClosing(WindowEvent e){
    System.exit(0);
         }
  });
  }

public void paint(Graphics g){

    g.setColor(Color.red);
    g.fillOval(xpos,ypos,100 ,100);
}

public void  keyPressed(KeyEvent e){
		int nKeycode=e.getKeyCode();
		if(nKeycode==KeyEvent.VK_LEFT)
		   xpos=xpos-10;
		   if(nKeycode==KeyEvent.VK_RIGHT)
		   xpos=xpos+10;
		   if(nKeycode==KeyEvent.VK_UP)
		   ypos=ypos-10;
		   if(nKeycode==KeyEvent.VK_DOWN)
		   ypos=ypos+10;
             repaint();
        }


        public void  keyReleased(KeyEvent e){}

 public void  keyTyped(KeyEvent e){}

}