#region 获取微信凭证        public string GetAccessToken(string wechat_id)        {            string accessToken = "";            DataTable dtwecaht = wechatdal.GetList("wechat_id=‘" + wechat_id + "‘").Tables[0];            if (dtwecaht.Rows.Count > 0)            {                string respText = "";                string wechat_appid = dtwecaht.Rows[0]["wechat_appid"].ToString();                string wechat_appsecret = dtwecaht.Rows[0]["wechat_appsecret"].ToString();                string url = string.Format(getAccessTokenUrl, wechat_appid, wechat_appsecret);                HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);                HttpWebResponse response = (HttpWebResponse)request.GetResponse();                using (Stream resStream = response.GetResponseStream())                {                    StreamReader reader = new StreamReader(resStream, Encoding.Default);                    respText = reader.ReadToEnd();                    resStream.Close();                }                JavaScriptSerializer Jss = new JavaScriptSerializer();                Dictionary<string, object> respDic = (Dictionary<string, object>)Jss.DeserializeObject(respText);                accessToken = respDic["access_token"].ToString();            }            return accessToken;        }        #endregion 获取微信凭证