C# 生成小程序码

 /// <summary>
 /// B接口-微信小程序带参数二维码的生成
 /// </summary>
 /// <param name="access_token"></param>
 /// <returns></returns>
 public static string CreateWxCode(string access_token string roomId)
 {
     string ret = string.Empty;
     try
     {
         string page = ConfigurationManager.AppSettings["page"].ToString();

         string DataJson = string.Empty;
         //适用于需要的码数量极多，或仅临时使用的业务场景
         //通过该接口生成的小程序码，永久有效，数量暂无限制。
         string url = "wxa/getwxacodeunlimit?access_token=" + access_token;
         DataJson = "{";
         DataJson += string.Format("'scene':'{0}'" "1234567");//所要传的参数用分看
         DataJson += string.Format("'width':'{0}'" 200);
         DataJson += string.Format("'page':'{0}'" page);//扫码所要跳转的地址，根路径前不要填加'/'不能携带参数（参数请放在scene字段里），如果不填写这个字段，默认跳主页面
         DataJson += "'line_color':{";
         DataJson += string.Format("'r':'{0}'" "0");
         DataJson += string.Format("'g':'{0}'" "0");
         DataJson += string.Format("'b':'{0}'" "0");
         DataJson += "}";
         DataJson += "}";


         string jsondata = JsonConvert.Serializeobxxxxject(DataJson);
         //DataJson的配置见小程序开发文档，B接口：https://mp.weixin.qq.com/debug/wxadoc/dev/api/qrcode.html
         ret = CreateWeChatQrCode(url jsondata);
     }
     catch (Exception e)
     {
         ret = e.Message;
     }
     return ret;//返回图片地址
 }


 /// <summary>
 /// 返回二维码图片
 /// </summary>
 /// <param name="url"></param>
 /// <param name="param"></param>
 /// <returns></returns>
 public static string CreateWeChatQrCode(string url string param)
 {
     string wechatapi = ConfigurationManager.AppSettings["wechatapi"].ToString();
     string qrcodepath = ConfigurationManager.AppSettings["qrcodepath"].ToString();
     string strURL = wechatapi+ url;
     HttpWebRequest request;
     string imgName = string.Empty;
     string path = string.Empty;
     try
     {
     request = (System.Net.HttpWebRequest)WebRequest.Create(strURL);


     request.Method = "POST";
     request.ContentType = "application/json;charset=UTF-8";
     string paraUrlCoded = param;
     //byte[] payload;
     byte[] payload = System.Text.Encoding.UTF8.GetBytes(paraUrlCoded);
     request.ContentLength = payload.Length;
     Stream writer = request.GetRequestStream();
     writer.Write(payload 0 payload.Length);
     writer.Close();
     System.Net.HttpWebResponse response;
     response = (System.Net.HttpWebResponse)request.GetResponse();
     System.IO.Stream s;
     s = response.GetResponseStream();//返回图片数据流

     byte[] tt = StreamToBytes(s);//将数据流转为byte[]


     //在文件名前面加上时间，以防重名
     imgName = DateTime.Now.ToString("yyyyMMddhhmmss") + ".jpg";
     //文件存储相对于当前应用目录的虚拟目录
     path = qrcodepath + "EWM/";


     //获取相对于应用的基目录创建目录
     string imgPath = System.Web.Hosting.HostingEnvironment.MapPath(path);//System.AppDomain.CurrentDomain.baxxxxseDirectory + path;     //通过此对象获取文件名
     if (!Directory.Exists(imgPath))
     {
         Directory.CreateDirectory(imgPath);
     }
     System.IO.File.WriteAllBytes(HttpContext.Current.Server.MapPath(path + imgName) tt);//讲byte[]存储为图片
     }
     catch (Exception ex)
     {
         ExceptionPolicy.HandleException(ex LZExceptionType.System
              "生成小程序二维码失败!源:Lz.Product.LJXQJGF.BLL.Files.CreateWeChatQrCode方法出错 ");
     }
     return path + imgName;
 }




 /// <summary>
 /// 将数据流转为byte[]
 /// </summary>
 /// <param name="stream"></param>
 /// <returns></returns>
 public static byte[] StreamToBytes(Stream stream)
 {
     List<byte> bytes = new List<byte>();
     int temp = stream.ReadByte();
     while (temp != -1)
     {
         bytes.Add((byte)temp);
         temp = stream.ReadByte();
     }
     return bytes.ToArray();
 }

获取access_token请参考我的另外一篇博客：https://www.cnblogs.com/qinaqina/p/11610346.html