using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class UsingDelegates
    {
       
        static void Main(string[] args)
        {
            long length1=10;
            long length2 = 15;
           
            Console.WriteLine("边长为{0}的正方形面积为：{1}",length1,Square (length1).ToString ());
            Console.WriteLine("半径为{0}的圆形面积为：{1}", length2, Circle(length2).ToString());
            Console.ReadLine();


        }
   
   
   
        public static double Square(long length)
        {
            double area;
            area = Math.Pow(length, 2);
            return area;
        }
        public static double Circle(long length)
        {
            double area;
            area = (4 / 3) * Math.PI * Math.Pow(length, 3);
            return area;
        }
    }
}




using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class UsingDelegates
    {
        public delegate double myDelegate(long length);
        static void Main(string[] args)
        {
            long length1 = 10;
            long length2 = 15;
            myDelegate myDelegate1 = new myDelegate(Measure.Square);
            myDelegate myDelegeta2 = new myDelegate(Measure.Circle);
            Console.WriteLine("边长为{0}的正方形面积为：{1}", length1, myDelegate1(length1).ToString());
            Console.WriteLine("半径为{0}的圆形面积为：{1}", length2, myDelegeta2(length2).ToString());
            Console.ReadLine();


        }
    }
    class Measure
    {

        public static double Square(long length)
        {
            double area;
            area = Math.Pow(length, 2);
            return area;
        }
        public static double Circle(long length)
        {
            double area;
            area = (4 / 3) * Math.PI * Math.Pow(length, 3);
            return area;
        }
    }
}

求助各位，两段代码的区别及使用效果？谢谢了！

嗯，谢谢你的回答。我正在从面向过程向对象过渡，不是很能理解，希望详解。   
    想问下，下面这段代码怎么体现了其封装效果？另外，第一段代码是不是也可以理解为所有东西封装在一个类UsingDelegates中？期待你的回答，谢谢！