WXApi类：
#region 验证Token是否过期
        /// <summary>
        ///  验证Token是否过期
        ///</summary>
        public static bool TokenExpired(string access_token)
        {
            string jsonStr = HttpRequestUtil.RequestUrl(string.Format("https://api.weixin.qq.com/cgi-bin/menu/get?access_token={0}", access_token));
            if (Tools.GetJsonValue(jsonStr, "errcode") == "42001")
            {
                return true;
            }
            return false;
        }
        #endregion
        #region 获取Token
        /// <summary>
        ///  获取Token
        /// </summary>
        public static string GetToken(string appid, string secret)
        {
            string strJson = HttpRequestUtil.RequestUrl(string.Format("https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid={0}&secret={1}", appid, secret));
            return Tools.GetJsonValue(strJson, "access_token");
        }
        #endregion

Tools类：
 #region 获取Json字符串某节点的值 
        /// <summary>  
        /// /// 获取Json字符串某节点的值  
        /// /// </summary>  
        public static string GetJsonValue(string jsonStr, string key)
        {
            string result = string.Empty; if (!string.IsNullOrEmpty(jsonStr))
            {
                key = "\"" + key.Trim(‘"‘) + "\""; int index = jsonStr.IndexOf(key) + key.Length + 1;
                if (index > key.Length + 1)
                {
                    //先截逗号，若是最后一个，截“｝”号，取最小值    
                    int end = jsonStr.IndexOf(‘,‘, index); if (end == -1)
                    {
                        end = jsonStr.IndexOf(‘}‘, index);
                    }
                    result = jsonStr.Substring(index, end - index);
                    result = result.Trim(new char[] { ‘"‘, ‘ ‘, ‘\‘‘ }); //过滤引号或空格 
                }
            }
            return result;
        }
        #endregion

HttpRequestUtil类：
 #region 请求Url，不发送数据
        /// <summary> 
        /// 请求Url，不发送数据
        /// </summary>
        public static string RequestUrl(string url)
        {
            return RequestUrl(url, "POST");
        }
        #endregion
        #region 请求Url，不发送数据
        /// <summary>
        /// 请求Url，不发送数据
        /// </summary>
        public static string RequestUrl(string url, string method)
        {
            // 设置参数 
            HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;
            CookieContainer cookieContainer = new CookieContainer();
            request.CookieContainer = cookieContainer;
            request.AllowAutoRedirect = true;
            request.Method = method;
            request.ContentType = "text/html";
            //request.GetRequestStream()
            //request.
            request.Headers.Add("charset", "utf-8");  //发送请求并获取相应回应数据
            Stream postStream = request.GetRequestStream();
            //postStream.Write(,0,bytearra)
            HttpWebResponse response = request.GetResponse() as HttpWebResponse;//直到request.GetResponse()程序才开始向目标网页发送Post请求
            //Stream responseStream = 
            StreamReader sr = new StreamReader(response.GetResponseStream(), Encoding.UTF8);//返回结果网页（html）代码             
            string content = sr.ReadToEnd();
            return content;
        }
        #endregion
        

下面是会返回错误44002的：原因是post数据未发送(没有提交数据)，也是控制器中：
  #region 请求Url，不发送数据
        /// <summary> 
        /// 请求Url，不发送数据
        /// </summary>
        public static string RequestUrl(string url)
        {
            return RequestUrl(url, "POST");
        }
        #endregion
        #region 请求Url，不发送数据
        /// <summary>
        /// 请求Url，不发送数据
        /// </summary>
        public static string RequestUrl(string url, string method)
        {
            // 设置参数 
            HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;
            CookieContainer cookieContainer = new CookieContainer();
            request.CookieContainer = cookieContainer;
            request.AllowAutoRedirect = true;
            request.Method = method;
            request.ContentType = "textml";
            request.Headers.Add("charset", "utf-8");  //发送请求并获取相应回应数据
            HttpWebResponse response = request.GetResponse() as HttpWebResponse;
            //直到request.GetResponse()程序才开始向目标网页发送Post请求
            Stream responseStream = response.GetResponseStream();
            StreamReader sr = new StreamReader(responseStream, Encoding.UTF8);
            //返回结果网页（html）代码 
            string content = sr.ReadToEnd();
            return content;
        }
        #endregion