接入微信电子发票流程步骤

一、流程图

　　电子发票流程涉及用户、商户、报销方、发票平台和公众平台五个角色。
　　对于自建发票平台的商户，发票平台即为商户自身的开票系统，承担着制作发票卡券、将发
　　票卡券插入用户卡包以及报销状态更新的关键作用。

二、步骤及页面

　　步骤1：检查是否微信打开

　　步骤2：检查微信版本是否高于或者等于6.0.2版本

//"Mozilla/5.0(iphone;CPU iphone OS 5_1_1 like Mac OS X)
//AppleWebKit / 534.46(KHTML, like Geocko)Mobile / 9B206 MicroMessenger/ 6.0.2 "
//其中6.0.2为用户安装的微信版本号。商户可以判定版本号是否高于或者等于6.0.2。

　　步骤3：检查发票是否真实存在

　　步骤4：获取微信token

        /// <summary>
        ///获取微信token
        /// </summary>
        /// <returns></returns>
        public static string GetToken()
        {
            string CGIBaseUrl = GlobalConfig.Settings["WechartBaseUrl"];
            string AppId = GlobalConfig.Settings["EfpgjAppId"];
            string security = GlobalConfig.Settings["EfpgjSecurity"];
            ObjectCache oCache = MemoryCache.Default;
            string fileContents = oCache["wechart_token"] as string;
            if (fileContents == null)
            {
                var url = string.Format("{0}/token?grant_type=client_credential&appid={1}&secret={2}",
                CGIBaseUrl + "/cgi-bin", AppId, security);
                using (WebClient client = new WebClient())
                {
                    client.Encoding = Encoding.UTF8;
                    string data = client.DownloadString(url);
                    var result = JObject.Parse(data);
                    if (result["access_token"] != null && result["access_token"].Value<string>() != string.Empty)
                    {
                        CacheItemPolicy policy = new CacheItemPolicy();
                        policy.AbsoluteExpiration = DateTime.Now.AddMinutes(120);//取得或设定值，这个值会指定是否应该在指定期间过后清除
                        fileContents = result["access_token"].Value<string>();
                        oCache.Set("wechart_token", fileContents, policy);
                    }
                }
            }
            return fileContents;
        }    

　　步骤5：获取发票平台 s_pappid

　　步骤6：获取发票 ticket

        /// <summary>
        /// 获取临时Ticket
        /// </summary>
        /// <param name="token"></param>
        /// <returns></returns>
        public static string GetTicket(string token)
        {
            ObjectCache oCache = MemoryCache.Default;
            string fileContents = oCache["wechart_ticket"] as string;
            if (fileContents == null)
            {
                string CGIBaseUrl = GlobalConfig.Settings["WechartBaseUrl"];
                var url = string.Format("{0}/cgi-bin/ticket/getticket?access_token={1}&type=wx_card",
                    CGIBaseUrl, token);
                var data = string.Empty;
                var arg = new
                {
                    access_token = token
                };
                var paramStr = JsonConvert.SerializeObject(arg);
                using (var client = new WebClient())
                {
                    client.Encoding = Encoding.UTF8;
                    data = client.UploadString(url, paramStr);
                }
                var result = JObject.Parse(data);
                CacheItemPolicy policy = new CacheItemPolicy();
                policy.AbsoluteExpiration = DateTime.Now.AddMinutes(120);//取得或设定值，这个值会指定是否应该在指定期间过后清除
                fileContents = result["ticket"].Value<string>();
                oCache.Set("wechart_ticket", fileContents, policy);
            }
            return fileContents;
        }

　　步骤7：获取授权页链接URL

        /// <summary>
        /// 获取授权页链接
        /// </summary>
        /// <param name="CGIBaseUrl"></param>
        /// <param name="token"></param>
        /// <returns></returns>
        public static string GetAuthUrl(string token, EInvoice invoice, int flags)
        {
            var spid = CheckToken(token);
            try
            {
                string CGIBaseUrl = GlobalConfig.Settings["WechartBaseUrl"];
                var url = string.Format("{0}/card/invoice/getauthurl?access_token={1}",
                        CGIBaseUrl, token);
                var data = string.Empty;
                var arg = new
                {
                    s_pappid = spid,
                    order_id = invoice.SwiftNumber,
                    money = invoice.SummaryAmount * 100,
                    timestamp = ConvertDateTimeInt(DateTime.Now),
                    source = "web",
                    redirect_url = GlobalConfig.Settings["WechartEIUrl"] + "/#!/wechartCardReturn/" + invoice.Id+"/"+invoice.CustomerName + "/" + flags,
                    //redirect_url = "http://eiapp.chinacloudsites.cn" + "/#!/testInsertcardCpt/" + SwiftNumber,
                    ticket = GetTicket(token),
                    type = 2,//授权类型， 0：开票授权， 1：填写字段开票授权， 2：领票授权
                };
                var paramStr = JsonConvert.SerializeObject(arg);
                using (var client = new WebClient())
                {
                    client.Encoding = Encoding.UTF8;
                    data = client.UploadString(url, paramStr);
                }
                var result = JObject.Parse(data);
                if (result["auth_url"] != null && result["auth_url"].Value<string>() != string.Empty)
                {
                    return result["auth_url"].Value<string>();
                }
                else
                    return data;
            }
            catch (Exception ex)
            {
                return spid + "/" + token + "/" + ex.Message;
            }
        }

　　步骤8：步骤7接口字段：授权成功后跳转页面，此页面中进行创建卡券-将电子发票插入用户卡包中操作