反射应用的一个小DEMO【利用反射，自动将对象生成json字符串】

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

namespace ReflectionDemo
{
    class Program
    {
        static void Main(string[] args)
        {
            User userInfo1 = new User(1, "ZhangQin");
            User userInfo2 = new User(2, "DengJiang");
            User userInfo3 = new User(3, "WeiWei");
            List<User> userList = new List<User>();
            userList.Add(userInfo1);
            userList.Add(userInfo2);
            userList.Add(userInfo3);
            string json = userList.ToJSON();
            Console.WriteLine(json);
            Console.ReadLine();
        }
    }
    class User
    {
        private int id;
        private string name;
        public User(int id, string name)
        {
            this.id = id;
            this.name = name;
        }
        [ToJSONAtrribute]
        public int Id
        {
            get { return this.id; }
            set { this.id = value; }
        }
        [ToJSONAtrribute]
        public string Name
        {
            get { return this.name; }
            set { this.name = value; }
        }
    }

    [AttributeUsage(AttributeTargets.Property, Inherited = false)]
    public class ToJSONAtrribute : Attribute
    {
        public ToJSONAtrribute()
        {
        }
    }
    public static class ExensionJSON
    {
        public static string ToJSON<T>(this IEnumerable<T> source)
        {
            string returnValue = "";
            StringBuilder sb = new StringBuilder();
            sb.Append("[");
            foreach (T item in source)
            {
                sb.Append("{"); 
                Type typeInfo = item.GetType();
                PropertyInfo[] properties = typeInfo.GetProperties();
                foreach (PropertyInfo property in properties)
                {
                    object[] attrs = property.GetCustomAttributes(typeof(ToJSONAtrribute),false);
                    if (attrs != null)
                    {
                        foreach (ToJSONAtrribute attr in attrs)
                        {
                            if (attr != null)
                            {
                                sb.Append(string.Format("\"{0}\":\"{1}\",", property.Name, property.GetValue(item, null)));
                            }
                        }
                    }
                }
                sb.Append("},");
            }  
            sb.Append("]");
            returnValue = sb.ToString ();
            returnValue = Regex.Replace(returnValue,@"(,)(}|])","$2");
            return returnValue;
        }
    }
}