微信开发：生成带参数的公众号二维码（扫码关注、订阅）

        //微信公众号
        private static string OfficialAccountAppId => ConfigurationManager.AppSettings["OfficialAccountAppId"];
        private static string OfficialAccountAppSecret => ConfigurationManager.AppSettings["OfficialAccountAppSecret"];

        /// 

        /// 返回带参数（场景值）的公众号二维码图片地址
        /// 
        /// 
        [Route("weixin/createqrcode/withParam")]
        [HttpGet]
        public async Task GetOfficialAccountQRcodeWithParam(string scene_str)
        {
            var ticket = CreateQrCodeTicketAsync(scene_str);

            RestResponse result = new RestResponse();
            //通过ticket获取二维码对应的url
            result.COntent= QrCodeApi.GetShowQrCodeUrl(ticket);　　　　//利用盛派获取图片地址（本人对网络请求并不熟悉，这里只是知道调用该方法能够获取成功，这里并没有去细究）

            return result;
        }

        /// 

        /// 利用微信API创建二维码ticket
        /// 
        /// 场景值
        /// 
        private string CreateQrCodeTicketAsync(string scene_str)
        {
            var accessToken = WeiXinCommonBll.WxGetAccexxToken(OfficialAccountAppId, OfficialAccountAppSecret);　　　　//微信获取access_token的方法每天有请求次数限制，应该自己封装一下
            
            string wxurl = "https://api.weixin.qq.com/cgi-bin/qrcode/create?access_token=" + accessToken;
            string strJson = "{\"expire_seconds\": 86400, \"action_name\": \"QR_STR_SCENE\", \"action_info\": {\"scene\": {\"scene_str\": " + scene_str + "}}}";
            
            var result = Post(wxurl, strJson);
            if (result != null)
            {
                JObject jobect = JObject.Parse(result);
                string ticket = (string)jobect["ticket"];

                if (string.IsNullOrEmpty(ticket))
                {
                    return null;
                }
                return ticket;
            }
            return null;
        }

        private string Post(string wxurl, string strJson)
        {
            WebClient client = new WebClient();
            client.Credentials = CredentialCache.DefaultCredentials;

            string result = client.UploadString(wxurl, "POST", strJson);
            return result;
        }

        //微信公众号
        private static string OfficialAccountAppId => ConfigurationManager.AppSettings["OfficialAccountAppId"];
        private static string OfficialAccountAppSecret => ConfigurationManager.AppSettings["OfficialAccountAppSecret"];

        /// 

        /// 返回带参数（场景值）的公众号二维码图片地址
        /// 
        /// 
        [Route("weixin/createqrcode/withParam")]
        [HttpGet]
        public async Task GetOfficialAccountQRcodeWithParam(string scene_str)
        {
            RestResponse result = new RestResponse();
            var accessToken = WeiXinCommonBll.WxGetAccexxToken(OfficialAccountAppId, OfficialAccountAppSecret);

　　　　　　  //原以为真的只有为永久字符串的时候 scene_str 才会有效，但是经测试，其实临时字符串的时候也是可以用的！
            var qrTicket = await QrCodeApi.CreateAsync(accessToken, 500, 5, QrCode_ActionName.QR_STR_SCENE, scene_str);
            result.Content = QrCodeApi.GetShowQrCodeUrl(qrTicket.ticket);

            return result;
        }