C#微信公众号接口开发实例-高级接口-申请带参数的二维码

　　最近公司涉及到微信绑定用户，做了高级接口-申请带参数的二维码，总结了下微信开发接口。微信接口开发都是除了消息用的xml 回复基本上都是用json的形式传递信息（post/get），开发的方法基本都是一样的，以下以高级接口获取带参数的二维码为例，怎么做微信接口开发。

第一步：获取access_token,access_token是获取其他接口信息的钥匙，所有接口都需要调用access_token

　　　　　/// <summary>
        /// 拉取AccessToken，微信每天公共2000次AccessToken的获取，所以需要缓存AccessToken
        /// </summary>
        /// <returns>用户凭证：AccessToken</returns>
        public string getTokenSession(string appid,string appsecret)
        {
            string TokenSession;
            if (Session[AccessToken] != null)
            {
                TokenSession = Session[AccessToken].ToString();
            }
            else
            {
                TokenSession = addTokenSession(appid, appsecret);
            }
            return TokenSession;
        }

        /// <summary>
        /// 将AccessToken添加到缓存
        /// </summary>
        /// <returns>AccessToken</returns>
        public string addTokenSession(string appid, string appsecret)
        {
            //获取AccessToken
            string AccessToken = GetAccessToken(string appid, string appsecret);
            HttpContext.Current.Session[AccessToken] = AccessToken;
            HttpContext.Current.Session.Timeout = 7200;
            return AccessToken;
        }

        /// <summary>
        /// 获取AccessToken
        /// </summary>
        /// <returns>AccessToken</returns>
        public string GetAccessToken(string appid, string appsecret)
        {
            string accessToken = "";
            string respText = "";
            string url = string.Format("https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid={0}&secret={1}", appid, 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();
            }
            Dictionary<string, object> respDic = (Dictionary<string, object>)Jss.DeserializeObject(respText);
            accessToken = respDic["access_token"].ToString();
            return accessToken;
        }

第二步：利用access_token来获取带参数的二维码

　　　　　/// <summary>
        /// 调用微信接口获取带参数临时二维码的ticket
        /// 使用方法：https://mp.weixin.qq.com/cgi-bin/showqrcode?ticket=TICKET
        /// </summary>
        /// <param name="scene_id">二维码带的参数</param>
        /// <returns>json:ticket:换取二维码的凭证，expire_seconds:凭证有效时间，url:二维码解析后的地址。此处返回ticket 否则返回错误码</returns>
        public string GetQrcode(string appid, string appsecret, Int32 scene_id)
        {
            string QrcodeUrl = "https://api.weixin.qq.com/cgi-bin/qrcode/create?access_token={0}";//WxQrcodeAPI接口
            string AccessToken = getTokenSession(appid, appsecret);//拉取AccessToken
            QrcodeUrl = string.Format(QrcodeUrl, AccessToken);
            string PostJson = "{\"expire_seconds\": 1800, \"action_name\": \"QR_SCENE\", \"action_info\": {\"scene\": {\"scene_id\": " + scene_id + "}}}";
            string ReText = WebRequestPostOrGet(QrcodeUrl, PostJson);//post提交
            Dictionary<string, object> reDic = (Dictionary<string, object>)Jss.DeserializeObject(ReText);
            if (reDic.ContainsKey("ticket"))
            {
                return reDic["ticket"].ToString();//成功
            }
            else
            {
                return reDic["errcode"].ToString();//返回错误码
            }
        }

        /// <summary>
        /// 调用微信接口获取带参数永久二维码的ticket
        /// 使用方法：https://mp.weixin.qq.com/cgi-bin/showqrcode?ticket=TICKET
        /// </summary>
        /// <param name="scene_id">二维码带的参数</param>
        /// <returns>json:ticket:换取二维码的凭证，expire_seconds:凭证有效时间，url:二维码解析后的地址。此处返回ticket 否则返回错误码</returns>
        public string GetQrcode(string appid, string appsecret, string scene_str)
        {
            string QrcodeUrl = "https://api.weixin.qq.com/cgi-bin/qrcode/create?access_token={0}";//WxQrcodeAPI接口
            string AccessToken = getTokenSession(appid, appsecret);//拉取AccessToken
            QrcodeUrl = string.Format(QrcodeUrl, AccessToken);
            string PostJson = "{\"expire_seconds\": 1800, \"action_name\": \"QR_LIMIT_STR_SCENE\", \"action_info\": {\"scene\": {\"scene_str\": " + scene_str + "}}}";
            string ReText = WebRequestPostOrGet(QrcodeUrl, PostJson);//此处省略了 WebRequestPostOrGet即为WebHttpRequest发送Post请求
            Dictionary<string, object> reDic = (Dictionary<string, object>)Jss.DeserializeObject(ReText);
            if (reDic.ContainsKey("ticket"))
            {
                return reDic["ticket"].ToString();//成功
            }
            else
            {
                return reDic["errcode"].ToString();//返回错误码
            }
        }

第三步：将获取的ticket用https://mp.weixin.qq.com/cgi-bin/showqrcode?ticket=TICKET使用就完成了。

微信开发者文档：http://mp.weixin.qq.com/wiki/18/28fc21e7ed87bec960651f0ce873ef8a.html