主要用来推广并统计数据，当用户扫描带参数二维码时，微信会推送消息到我们的服务器，此时可以根据参数了解到用户是从哪个渠道关注的。话不多少，先来代码：
1 #region 生成二维码 2 3 ///4 /// 获取Ticket 5 /// 6 ///7 private static string CreateTicket(string scene_id) 8 { 9 var token = AccessToken.Instance; 10 11 if (string.IsNullOrEmpty(token.Access_Token)) 12 throw new ArgumentNullException("Access_Token"); 13 14 string url = string.Format(WeiXinConst.WeiXin_Ticket_CreateUrl, token.Access_Token); 15 string postData = WeiXinConst.WeiXin_QrCodeTicket_Create_JsonString.Replace("{0}", scene_id); 16 17 string result = HttpClientHelper.PostResponse(url, postData); 18 Ticket ticket = JsonConvert.DeserializeObject (result); //HttpClientHelper.PostResponse (url, postData); 19 20 if (ticket == null || string.IsNullOrEmpty(ticket.ticket)) 21 { 22 ErrorMessage msg = JsonConvert.DeserializeObject (result); 23 if (msg.TokenExpired) 24 return CreateTicketByNewAccessToken(scene_id); 25 } 26 return ticket.ticket; 27 } 28 29 /// 30 /// 当AccessToken过期时 调用此方法 31 /// 32 /// 33 ///34 private static string CreateTicketByNewAccessToken(string scene_id) 35 { 36 var token = AccessToken.NewInstance; 37 38 if (string.IsNullOrEmpty(token.Access_Token)) 39 throw new ArgumentNullException("Access_Token"); 40 41 string url = string.Format(WeiXinConst.WeiXin_Ticket_CreateUrl, token.Access_Token); 42 string postData = WeiXinConst.WeiXin_QrCodeTicket_Create_JsonString.Replace("{0}", scene_id); 43 44 Ticket ticket = HttpClientHelper.PostResponse (url, postData); 45 46 if (ticket == null || string.IsNullOrEmpty(ticket.ticket)) 47 throw new Exception("Ticket为Null，AccessToken:" + token.Access_Token); 48 return ticket.ticket; 49 } 50 51 52 /// 53 /// 根据Ticket获取二维码图片保存在本地 54 /// 55 /// 二维码场景id 56 /// 图片存储路径 57 public static void SaveQrCodeImage(string scene_id, string imgPath) 58 { 59 string Ticket = CreateTicket(scene_id); 60 61 if (Ticket == null) 62 throw new ArgumentNullException("Ticket"); 63 64 //ticket需 urlEncode 65 string stUrl = string.Format(WeiXinConst.WeiXin_QrCode_GetUrl, HttpUtility.UrlEncode(Ticket)); 66 67 HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(stUrl); 68 69 req.Method = "GET"; 70 71 using (WebResponse wr = req.GetResponse()) 72 { 73 HttpWebResponse myResponse = (HttpWebResponse)req.GetResponse(); 74 string strpath = myResponse.ResponseUri.ToString(); 75 76 WebClient mywebclient = new WebClient(); 77 78 try 79 { 80 mywebclient.DownloadFile(strpath, imgPath); 81 } 82 catch (Exception) 83 { 84 throw new Exception("获取二维码图片失败！"); 85 } 86 } 87 } 88 89 ///90 /// 根据SceneId 获取 二维码图片流 91 /// 92 /// 93 ///94 public static Stream GetQrCodeImageStream(string scene_id) 95 { 96 string Ticket = CreateTicket(scene_id); 97 98 if (Ticket == null) 99 throw new ArgumentNullException("Ticket"); 100 101 //ticket需 urlEncode 102 string strUrl = string.Format(WeiXinConst.WeiXin_QrCode_GetUrl, HttpUtility.UrlEncode(Ticket)); 103 try 104 { 105 System.Net.Http.HttpClient client = new System.Net.Http.HttpClient(); 106 Byte[] bytes = client.GetByteArrayAsync(strUrl).Result; 107 return new MemoryStream(bytes); 108 } 109 catch 110 { 111 throw new Exception("获取二维码图片失败！"); 112 } 113 } 114 115 #endregion
生成带参数的二维码，需要先获取Ticket（内置 token过期处理），再根据Ticket获取二维码（两个方法：保存到本地 以及 返回Stream）。
下面是调用代码：
1 string scene_id = "1";//场景Id，扫描生产的二维码 会带这个id，可以做推广、统计用
2
3 //获取二维码流
4 System.IO.Stream stream = WeiXinHelper.GetQrCodeImageStream(scene_id);
5
6 //二维码图片存储路径
7 string path = Server.MapPath("~/Document/QrCode/" + scene_id + ".jpg");
8 //直接保存二维码到本地
9 WeiXinHelper.SaveQrCodeImage("1", path);
