C#微信公众平台开发（1）

      private string Token = ConfigurationManager.AppSettings["Token"];

        [HttpGet]
        [ActionName("Index")]
        public ActionResult Get(string signature, string timestamp, string nonce, string echostr)
        {
            if (CheckSignature.Check(signature, timestamp, nonce, Token))
            {
                return Content(echostr);//返回随机字符串则表示验证通过
            }
            else
            {
                return Content("failed:" + signature + "," + CheckSignature.GetSignature(timestamp, nonce, Token) + "。如果你在浏览器中看到这句话，说明此地址可以被作为微信公众账号后台的Url，请注意保持Token一致。");
            }
        }
       /// 

        /// 检查签名是否正确
        /// 
        /// 
        /// 
        /// 
        /// 
        /// 
        public static bool Check(string signature, string timestamp, string nonce, string token = null)
        {
            return signature == GetSignature(timestamp, nonce, token);
        }

        /// 

        /// 返回正确的签名
        /// 
        /// 
        /// 
        /// 
        /// 
        public static string GetSignature(string timestamp, string nonce, string token = null)
        {
            token = token ?? Token;
            var arr = new[] { token, timestamp, nonce }.OrderBy(z => z).ToArray();
            var arrString = string.Join("", arr);
            //var enText = FormsAuthentication.HashPasswordForStoringInConfigFile(arrString, "SHA1");//使用System.Web.Security程序集
            var sha1 = System.Security.Cryptography.SHA1.Create();
            var sha1Arr = sha1.ComputeHash(Encoding.UTF8.GetBytes(arrString));
            StringBuilder enText = new StringBuilder();
            foreach (var b in sha1Arr)
            {
                enText.AppendFormat("{0:x2}", b);
            }

            return enText.ToString();
        }