protected void Page_Load(object sender, EventArgs e)
        {

            if (Request.RequestType.ToLower().Equals("post"))
            {
                //接收消息
                ResponseMsg();
            }
            else
            {
                //校验接口
                CheckSignature();
            }
            Response.End();
        }

 /// 
        /// 校验方法
        /// 
        private void CheckSignature()
        {
            try
            {
                //1获取微信服务器传过来的四个参数
                string signature = Request.QueryString["signature"];
                string timestamp = Request.QueryString["timestamp"];
                string nonce = Request.QueryString["nonce"];
                string echostr = Request.QueryString["echostr"];//该字符串用来成功验证后原样返回

                string token = TOKEN;
                string[] tmpArr = new string[] { token, timestamp, nonce };//2 对这三个参数进行“字典序排序”
                Array.Sort(tmpArr);
                string tmpStr = string.Join("", tmpArr);//3 拼接三个字符串
                tmpStr = FormsAuthentication.HashPasswordForStoringInConfigFile(tmpStr, "SHA1");//4 sha1加密
                tmpStr = tmpStr.ToLower();
                if (tmpStr == signature)
                {
                    SetCacheDateTime("Item", tmpStr + ":" + signature + " " + echostr, 3600);
                    //4 成功验证原样返回
                    HttpContext.Current.Response.Write(echostr);
                }
                else {
                    SetCacheDateTime("Item", "验证不通过", 3600);
                    Response.Write("验证不通过");//随便返回
                }
            }
            catch (Exception ex)
            {
                SetCacheDateTime("Item", ex.Message, 3600);
                Response.Write(ex.Message);//随便返回
            }