C#创建委托实例

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
 
namespace MyDelegate
{
    class Program
    {
        static void Main(string[] args)
        {
            List<User> users = GetUsers();
 
            //1.传统方式实例化委托实例
            users = users.OrderBy(new Func<User, int>(OrderType)).ToList();
 
            //2.委托参数采用匿名函数代替函数名
            users = users.OrderBy(new Func<User, int>(delegate(User user)
            {
                return user.Number;
            })).ToList();
 
            ////3.匿名函数直接创建委托实例
            users = users.OrderBy(delegate(User user)
            {
                return user.Number;
            }).ToList();
 
            ////4.lambda表达式本质：用于创建委托的匿名函数
            users = users.OrderBy(user => user.Number).ToList();
 
 
            //输出
            users.ForEach(x =>
            {
                Console.WriteLine("Number{0}:Name{1}:Age:{2}", x.Number, x.Name, x.Age);
            });
 
            //暂停
            Console.Read();
        }
 
 
        /// <summary>
        /// 排序方式
        /// </summary>
        /// <param name="arg"></param>
        /// <returns></returns>
        private static int OrderType(User user)
        {
            return user.Number;  //按照编号排序
        }
 
        private static List<User>  GetUsers()
        {
            List<User> users = new List<User>();
            User user1 = new User(3, "张三", 19);
            User user2 = new User(2, "李四", 27);
            User user3 = new User(1, "王五", 12);
            users.Add(user1);
            users.Add(user2);
            users.Add(user3);
            return users;
        }
    }
}