通过实例可以更好的了解java

7-例子1
import java.applet.*;import java.awt.*;
public class Example7_1 extends Applet
{Button button1; Button button2;
    int sum;
    public void init()
    { button1=new Button("yes");
      button2=new Button("No");  
      add(button1);
      add(button2);     
    }
    public void start()
    {  sum=0;
        for(int i=1;i<=100;i++)
         {sum=sum+i;}
    }
    public void stop()
    { }
    public void destroy()
    { }
    public void paint(Graphics g)
    {g.setColor(Color.blue); 
     g.drawString("程序设计方法",20,60);
     g.setColor(Color.red);
     g.drawString("sum=  ",20,100);
    }
}



7-例子2
import java.applet.*;
import java.awt.*;
public class Example7_2 extends Applet
{ int initcount=0,startcount=0,stopcount=0,destroycount=0,paintcount=0;
   public void init()
   { initcount=initcount+1;}
   public void start()
   { startcount++;}
   public void stop()
   { stopcount++;}
   public void destroy()
   { destroycount++;}
   public void paint(Graphics g)
   { paintcount++;
     g.drawString("initcount   ="+initcount,10,20);
     g.drawString("startcount  ="+startcount,10,40); 
     g.drawString("stopcount   ="+stopcount,10,60);
     g.drawString("deatroycount="+destroycount,10,80);     
     g.drawString("paintcount  ="+paintcount,10,100);
   }
}



7-例子3
import java.applet.*;import java.awt.*;
public class Example7_3 extends Applet 
{  int x;
   public void init()
   {  x=5;  }   
  public void start()
   { x=x+20;  repaint(); }
  public void stop()   {}
   public void paint(Graphics g)
   {g.drawString("我们是大学生",20,x+10); }   
}