C#基础知识整理：C#类和结构（1）

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

namespace TestStruct
{
    class Program
    {
        public struct Circle     //定义一个圆
        {
            private const double pi = 3.1415926;

            public double radius;  //半径

            /// 

            /// 构造函数
            /// 
            public Circle(double r)
            {
                radius = r;
            }
            /// 

            /// 面积
            /// 
            public double CArea()
            {
                return 3.14 * radius * radius;
            }

        }

        static void Main(string[] args)
        {
            Circle circle1;    //不用new实例化

            circle1.radius = 5;

            Console.WriteLine("圆面积为：" + circle1.CArea());

            Circle circle2 = new Circle(1);  //用new实例化

            Console.WriteLine("圆面积为：" + circle2.CArea());

            Console.ReadLine();
        }
    }
}

  class Program
    {
        public delegate void PrinteDelegate(string name);

        private static void PrinteEnglish(string name)
        {
            Console.WriteLine("Your Name: " + name);
        }

        private static void PrinteChinese(string name)
        {
            Console.WriteLine("你的大名： " + name);
        }

        private static void Printe(string name, PrinteDelegate MakeGreeting)
        {
            MakeGreeting(name);
        }

        static void Main(string[] args)
        {
            Printe("Sam Young", PrinteEnglish);

            Printe("白杨树", PrinteChinese);

            Console.ReadLine();
        }
    }