效果如下:
代码实现:
1. 获取临时二维码 ticket
- /// <summary>
- /// 获取临时二维码 ticket
- /// </summary>
- /// <param name="scene_str"> 场景值 ID openid 做场景值 ID</param>
- /// <returns></returns>
- public static string CreateTempQRCode(string scene_str,string access_token)
- {
- var result = HttpUtility.SendPostHttpRequest($"https://api.weixin.qq.com/cgi-bin/qrcode/create?access_token={access_token}", "application/json", "{\"expire_seconds\": 2592000, \"action_name\": \"QR_STR_SCENE\", \"action_info\": {\"scene\": {\"scene_str\": \"" + scene_str + "\"}}}");
- JObject jobect = (JObject)JsonConvert.DeserializeObject(result);
- string ticket = (string)jobect["ticket"];
- if (string.IsNullOrEmpty(ticket))
- {
- LogHelper.WriteLog(typeof(WeixinHelper), "获取临时二维码 ticket 失败" + result);
- return null;
- }
- return ticket;
- }
使用 openid 作为场景值的好处是通过扫 A 推广的二维码关注用户的场景值便是 A 的 openid.
2. 生成带二维码的专属推广图片
- /// <summary>
- /// 生成带二维码的专属推广图片
- /// </summary>
- /// <param name="user"></param>
- /// <returns></returns>
- public string Draw(WxUser user)
- {
- // 背景图片
- string path = Server.MapPath("/Content/images/tg.jpg");
- System.Drawing.Image imgSrc = System.Drawing.Image.FromFile(path);
- // 处理二维码图片大小 240*240px
- System.Drawing.Image qrCodeImage = ReduceImage("https://mp.weixin.qq.com/cgi-bin/showqrcode?ticket="+user.ticket, 240, 240);
- // 处理头像图片大小 100*100px
- Image titleImage = ReduceImage(user.headimgurl, 100, 100);
- using (Graphics g = Graphics.FromImage(imgSrc))
- {
- // 画专属推广二维码
- g.DrawImage(qrCodeImage, new Rectangle(imgSrc.Width - qrCodeImage.Width - 200,
- imgSrc.Height - qrCodeImage.Height - 200,
- qrCodeImage.Width,
- qrCodeImage.Height),
- 0, 0, qrCodeImage.Width, qrCodeImage.Height, GraphicsUnit.Pixel);
- // 画头像
- g.DrawImage(titleImage, 8, 8, titleImage.Width, titleImage.Height);
- Font font = new Font("宋体", 30, FontStyle.Bold);
- g.DrawString(user.nickname, font, new SolidBrush(Color.Red), 110, 10);
- }
- string newpath = Server.MapPath(@"/Content/images/newtg_" + Guid.NewGuid().ToString() + ".jpg");
- imgSrc.Save(newpath, System.Drawing.Imaging.ImageFormat.Jpeg);
- return newpath;
- }
- /// <summary>
- /// 缩小 / 放大图片
- /// </summary>
- /// <param name="url"> 图片网络地址 </param>
- /// <param name="toWidth"> 缩小 / 放大宽度 </param>
- /// <param name="toHeight"> 缩小 / 放大高度 </param>
- /// <returns></returns>
- public Image ReduceImage(string url, int toWidth, int toHeight)
- {
- webRequest request = WebRequest.Create(url);
- WebResponse response = request.GetResponse();
- Stream responseStream = response.GetResponseStream();
- Image originalImage = Image.FromStream(responseStream);
- if (toWidth <= 0 && toHeight <= 0)
- {
- return originalImage;
- }
- else if (toWidth> 0 && toHeight> 0)
- {
- if (originalImage.Width <toWidth && originalImage.Height < toHeight)
- return originalImage;
- }
- else if (toWidth <= 0 && toHeight> 0)
- {
- if (originalImage.Height <toHeight)
- return originalImage;
- toWidth = originalImage.Width * toHeight / originalImage.Height;
- }
- else if (toHeight <= 0 && toWidth> 0)
- {
- if (originalImage.Width <toWidth)
- return originalImage;
- toHeight = originalImage.Height * toWidth / originalImage.Width;
- }
- Image toBitmap = new Bitmap(toWidth, toHeight);
- using (Graphics g = Graphics.FromImage(toBitmap))
- {
- g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
- g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
- g.Clear(Color.Transparent);
- g.DrawImage(originalImage,
- new Rectangle(0, 0, toWidth, toHeight),
- new Rectangle(0, 0, originalImage.Width, originalImage.Height),
- GraphicsUnit.Pixel);
- originalImage.Dispose();
- return toBitmap;
- }
- }
3. 将图片上传微信服务器, 并发送给用户
- string imagePath = Draw(user);
- string result = HttpUtility.UploadFile($"https://api.weixin.qq.com/cgi-bin/material/add_material?access_token={access_token}&type=image", imagePath);
- JObject jObject = (JObject)JsonConvert.DeserializeObject(result);
- string media_id = (string)jObject["media_id"];
- if (!string.IsNullOrEmpty(media_id))
- {
- string resxml = "<xml><ToUserName><![CDATA[" + xmlMsg.FromUserName + "]]></ToUserName><FromUserName><![CDATA[" + xmlMsg.ToUserName + "]]></FromUserName><CreateTime>" + nowtime + "</CreateTime><MsgType><![CDATA[image]]></MsgType><Image><MediaId><![CDATA[" + media_id + "]]></MediaId></Image></xml>";
- return resxml;
- }
- LogHelper.WriteLog(typeof(WechatController), "上传专属推广图片素材失败" + result);
来源: https://www.cnblogs.com/gracexu/p/10081111.html