using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Reflection;namespace SomeTest{        class Program    {        static void Main(string[] args)        {            demo d = new demo();            string username = "Lucy";            MethodInfo mi = d.GetType().GetMethod("Test");            if (mi == null) return;            AllowExecuteAttribute att = Attribute.GetCustomAttribute(mi,typeof(AllowExecuteAttribute)) as AllowExecuteAttribute;            if (att == null) return;            if (att.Check(username))                Console.WriteLine("允许执行");            else                Console.WriteLine("不允许执行");            Console.ReadKey();        }    }    class demo    {        [AllowExecute("jack,Tom")]        public void Test()        {                     }    }    /// <summary>     /// 标识某方法允许执行的用户     /// </summary>     public class AllowExecuteAttribute : Attribute    {        /// <summary>         ///          /// </summary>         /// <param name="allowedUsers">允许执行的用户名的串联字符串</param>         public AllowExecuteAttribute(string allowedUsers)        {            this._allowedUsers = allowedUsers;        }        private string _allowedUsers;        public bool Check(string userName)        {            return this._allowedUsers.ToLower().IndexOf(userName.ToLower()) > -1;        }    }}

public class SingleUserAuthorize : AuthorizeAttribute    {        [ValidateInput(false)]        protected override bool AuthorizeCore(HttpContextBase httpContext)        {            Hashtable userOnline = (Hashtable)(httpContext.Application["Online"]);            if (userOnline != null)            {                IDictionaryEnumerator idE = userOnline.GetEnumerator();                string strkey = string.Empty;                if (userOnline.Count > 0)                {                    while (idE.MoveNext())                    {                        //登录时判断保存的session是否与当前页面的session相同                        if (userOnline.Contains(httpContext.Session.SessionID))                        {                            if (idE.Key != null && idE.Key.ToString().Equals(httpContext.Session.SessionID))                            {                                //判断当前session保存的值是否为被注销值                                if (idE.Value != null && "XXXXXX".Equals(idE.Value.ToString()))                                {                                    //验证被注销则清空session                                    userOnline.Remove(httpContext.Session.SessionID);                                    httpContext.Application.Lock();                                    httpContext.Application["Online"] = userOnline;                                    httpContext.Response.Write("<script>top.location.href=http://www.mamicode.com/‘/Home/Message?message=offline‘;</script>");                                    httpContext.Response.End();                                    return false;                                }                            }                        }                        else                        {                            return false;                        }                    }                    return true;                }                else                {                    return false;                }            }            return false;        }    }