微信Accesstoken通过xml文件方式保存

 　　　　//获取accessToken
        public static AccessToken GetAccessToken()
        {
            string AppID = JobBase.GetConfParamValue(ParamEnum.AppID);
            string AppSecret = JobBase.GetConfParamValue(ParamEnum.AppSecret);
            string accessTokenUrl = string.Format("https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid={0}&secret={1}", AppID, AppSecret);//
            string accessTokenJson = RequestHelper.SendGet(accessTokenUrl);
            JObject json = JObject.Parse(accessTokenJson);
            AccessToken Token = new AccessToken();
            Token.Access_token = json["access_token"].ToString().Replace(""", string.Empty).Trim();
            Token.Expires_in = json["expires_in"].ToString();//DateTime.Now.AddSeconds(Convert.ToInt32(json["expires_in"])).ToString();
            return Token;
        }


        public static string GetExistAccessToken()
        {
            // 读取XML文件中的数据        
            //string filePath = System.Web.HttpContext.Current.Server.MapPath("XML/Token.xml");
            //string filePath = "http://。。。/QYXML/Token.xml";     
            string filePath = JobBase.GetConfApiValue(IplatformEnum.TokenXML);
            FileStream fs = new FileStream(filePath, FileMode.Open, FileAccess.Read);
            XmlDocument xml = new XmlDocument();
            //xml.Load(filePath);
            xml.Load(fs);
            fs.Close();
            string Token = xml.SelectSingleNode("xml").SelectSingleNode("AccessToken").InnerText.ToString().Trim();
            DateTime AccessExpires = Convert.ToDateTime(xml.SelectSingleNode("xml").SelectSingleNode("AccessExpires").InnerText);
            if (DateTime.Now >= AccessExpires)
            {
                FileStream fstream = new FileStream(filePath, FileMode.Create, FileAccess.Write);
                AccessToken mode = GetAccessToken();
                xml.SelectSingleNode("xml").SelectSingleNode("AccessToken").InnerText = mode.Access_token;
                DateTime _accessExpires = DateTime.Now.AddSeconds(int.Parse(mode.Expires_in) - 900);//1h45min
                xml.SelectSingleNode("xml").SelectSingleNode("AccessExpires").InnerText = _accessExpires.ToString();
                //xml.Save(filePath);
                xml.Save(fstream);//此处文件保存容易报错，xml文件每次重写全覆盖不完全
                fstream.Close();
                Token = mode.Access_token;
            }
            return Token;
        }

        public static void UpdateXML(AccessToken mode)
        {
            string filePath = JobBase.GetConfApiValue(IplatformEnum.TokenXML);
            StreamReader sr = new StreamReader(filePath, System.Text.Encoding.UTF8);
            XmlDocument xmldoc = new XmlDocument();
            xmldoc.Load(sr);
            sr.Close();
            sr.Dispose();
            xmldoc.SelectSingleNode("xml").SelectSingleNode("AccessToken").InnerText = mode.Access_token;
            DateTime _accessExpires = DateTime.Now.AddSeconds(int.Parse(mode.Expires_in) - 900);
            xmldoc.SelectSingleNode("xml").SelectSingleNode("AccessExpires").InnerText = _accessExpires.ToString();
            xmldoc.Save(filePath);
        }