I need to upload files from client machine to a remote server and for that i have created a windows application which will work as client. It will select the required file and call the Web API.

Please find my client code as below :

 //...other code removed for brevity          private void UploadFile(string filename)     {         Stream ms = new MemoryStream();         using (FileStream file = new FileStream(filename, FileMode.Open, FileAccess.Read))         {             var fileInfo = new FileInfo(filename);             byte[] bytes = new byte[file.Length];             file.Read(bytes, 0, (int)file.Length);             ms.Write(bytes, 0, (int)file.Length);              MultiPartFormUpload multiPartFormUpload = new MultiPartFormUpload();             List<FileInfo> files = new List<FileInfo>() { fileInfo };              try             {                 MultiPartFormUpload.UploadResponse response = multiPartFormUpload.Upload("http://localhost:10458/api/Upload", files);             }             catch (Exception ex)             {                 throw ex;             }         }     }   public class MultiPartFormUpload {     public class MimePart     {         NameValueCollection _headers = new NameValueCollection();         byte[] _header;          public NameValueCollection Headers         {             get { return _headers; }         }          public byte[] Header         {             get { return _header; }         }          public long GenerateHeaderFooterData(string boundary)         {             StringBuilder stringBuilder = new StringBuilder();              stringBuilder.Append("--");             stringBuilder.Append(boundary);             stringBuilder.AppendLine();             foreach (string key in _headers.AllKeys)             {                 stringBuilder.Append(key);                 stringBuilder.Append(": ");                 stringBuilder.AppendLine(_headers[key]);             }             stringBuilder.AppendLine();              _header = Encoding.UTF8.GetBytes(stringBuilder.ToString());              return _header.Length + Data.Length + 2;         }          public Stream Data { get; set; }     }      public class UploadResponse     {         public UploadResponse(HttpStatusCode httpStatusCode, string responseBody)         {             HttpStatusCode = httpStatusCode;             ResponseBody = responseBody;         }          public HttpStatusCode HttpStatusCode { get; set; }          public string ResponseBody { get; set; }     }      public UploadResponse Upload(string url, List<FileInfo> files)     {         using (WebClient client = new WebClient())         {             List<MimePart> mimeParts = new List<MimePart>();              try             {                   foreach (FileInfo file in files)                 {                     MimePart part = new MimePart();                     string name = file.Extension.Substring(1);                     string fileName = file.Name;                      part.Headers["Content-Disposition"] = "form-data; name=\"" + name + "\"; filename=\"" + fileName + "\"";                     part.Headers["Content-Type"] = "application/octet-stream";                      part.Data = new MemoryStream(File.ReadAllBytes(file.FullName));                      mimeParts.Add(part);                 }                  string boundary = "----------" + DateTime.Now.Ticks.ToString("x");                 client.Headers.Add(HttpRequestHeader.ContentType, "multipart/form-data; boundary=" + boundary);                  long contentLength = 0;                  byte[] _footer = Encoding.UTF8.GetBytes("--" + boundary + "--\r\n");                  foreach (MimePart mimePart in mimeParts)                 {                     contentLength += mimePart.GenerateHeaderFooterData(boundary);                 }                  byte[] buffer = new byte[8192];                 byte[] afterFile = Encoding.UTF8.GetBytes("\r\n");                 int read;                  using (MemoryStream memoryStream = new MemoryStream())                 {                     foreach (MimePart mimePart in mimeParts)                     {                         memoryStream.Write(mimePart.Header, 0, mimePart.Header.Length);                          while ((read = mimePart.Data.Read(buffer, 0, buffer.Length)) > 0)                             memoryStream.Write(buffer, 0, read);                          mimePart.Data.Dispose();                          memoryStream.Write(afterFile, 0, afterFile.Length);                     }                      memoryStream.Write(_footer, 0, _footer.Length);                     byte[] responseBytes = client.UploadData(url, memoryStream.ToArray());                     string responseString = Encoding.UTF8.GetString(responseBytes);                     return new UploadResponse(HttpStatusCode.OK, responseString);                 }             }             catch (Exception ex)             {                 foreach (MimePart part in mimeParts)                     if (part.Data != null)                         part.Data.Dispose();                  if (ex.GetType().Name == "WebException")                 {                     WebException webException = (WebException)ex;                     HttpWebResponse response = (HttpWebResponse)webException.Response;                     string responseString;                      using (StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.UTF8))                     {                         responseString = reader.ReadToEnd();                     }                      return new UploadResponse(response.StatusCode, responseString);                 }                 else                 {                     throw;                 }             }         }     } } 

Please find Web API code as below :

    public async Task<HttpResponseMessage> Post()     {         if (!Request.Content.IsMimeMultipartContent())         {             throw new HttpResponseException(HttpStatusCode.UnsupportedMediaType);         }          string fileSaveLocation = HttpContext.Current.Server.MapPath("~/upload/files");         CustomMultipartFormDataStreamProvider provider = new CustomMultipartFormDataStreamProvider(fileSaveLocation);         List<string> files = new List<string>();          try         {             await Request.Content.ReadAsMultipartAsync(provider);              foreach (MultipartFileData file in provider.FileData)             {                 files.Add(Path.GetFileName(file.LocalFileName));             }              // Send OK Response along with saved file names to the client.             return Request.CreateResponse(HttpStatusCode.OK, files);         }         catch (System.Exception e)         {             return Request.CreateErrorResponse(HttpStatusCode.InternalServerError, e);         }     }      public class CustomMultipartFormDataStreamProvider : MultipartFormDataStreamProvider     {     public CustomMultipartFormDataStreamProvider(string path) : base(path) { }      public override string GetLocalFileName(HttpContentHeaders headers)     {         return headers.ContentDisposition.FileName.Replace("\"", string.Empty);     } } 

I am able to hit the Web API with the client code but fileInfo.Length is coming 0.

Please let me know what i am missing in Client or Web API code. Thanks !