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}'" "");//所要传的参数用分看
          DataJson += string.Format("'width':'{0}'" );
          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}'" "");
          DataJson += string.Format("'g':'{0}'" "");
          DataJson += string.Format("'b':'{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  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 != -)
      {
          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