movecircle.java

用JAVA APPLET开发的小游戏,介绍了鼠标和键盘的事件响应,是初学JAVA EVENT LISTENER 的例子教程.

import java.awt.*;

public class movecircle extends Thread

{   int x,y,dx,dy,r;     //x,y是movecircle的圆心,dx,dy是移动的距离,r是半径
    private Color co;
  
    

    movecircle(int a,int b,int c,int d,int e)
    {  x=a;
       y=b;
       dx=c;
       dy=d;
       r=e;          co=randomcolor();
      
    }
    
    public void run()
    {  try{
          while(true)
          {   move();
              Thread.sleep(100);
          }
       }
       catch(Exception e)
       {}
    }  
    
    public void draw(Graphics g)               //显示园
    {  g.setColor(co);
       g.fillOval(x-r,y-r,2*r,2*r);
    }
    
    public void move()                  //移动园
    {   x=x+dx;
        y=y+dy;
        bound(384,384);
    }
    
    private void bound(int w,int h)        //园的反弹
    {   if((x-r<0) | (x+r>w))
           {dx=-dx;}
        if((y-r<0) | (y+r>h))
           {dy=-dy;}
    }
    
    public Color randomcolor()
    {   Color co1;
        int a=(int)Math.floor(Math.random()*10);          //算出随机数0=<a,b<=10
        
        if(a<1) 
            co1=Color.blue;
        else if(a<2)
            co1=Color.black;
        else if(a<3)
            co1=Color.red;
        else if(a<4)
            co1=Color.cyan;
        else if(a<5)
            co1=Color.DARK_GRAY;
        else if(a<6)
            co1=Color.gray;
        else if(a<7)
            co1=Color.yellow;
        else if(a<8)
            co1=Color.PINK;
        else if(a<9)
            co1=Color.magenta;                               
        else
            co1=Color.green;
        return co1;
    }
}