List转换为json

 List<T_USER_INNER> users = db.T_USER_INNER.ToList();
            DataContractJsonSerializer json = new DataContractJsonSerializer(users.GetType());
            using (MemoryStream stream = new MemoryStream())
            {

                json.WriteObject(stream, users);
                string a = Encoding.UTF8.GetString(stream.ToArray());
                context.Response.Write(a);
            }

 命名空间：

using System.Runtime.Serialization.Json;
using System.IO;
using System.Text;

方法二：或者用插件

using System;
using System.IO;
using System.Text;
using Newtonsoft.Json;

namespace EasyUIBLL
{
    public class JsonTools
    {
        // 从一个对象信息生成Json串
        public static string ObjectToJson(object obj)
        {
            return JsonConvert.SerializeObject(obj);
        }
    }
}