Dear Stefan,

Thank you for your quick reply.  Based on your JAVA code and searches on the internet, I managed to move forward but I am still not successful. At least my POST method runs to completion but it returns an error message:

{"errors":[{"code":401,"type":"UNAUTHORIZED","message":"No session token provided."}]}

Based on inspections I made, I suspect that the boundary is the reason of the problem but I can't find the reason why. All this is new land to me and I made a lot of tries before contacting you.

Have you any hint/idea about the reason of the problem. Below is my code.

Thanks in advance for your support.

Regards,

Laurent

var client = new HttpClient();

client.BaseAddress = new Uri(srvAddress);

client.DefaultRequestHeaders.Accept.Clear();

client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

string boundary = "----------------------------" + DateTime.Now.Ticks.ToString("x");

Stream rs = new MemoryStream();

var endBoundaryBytes = System.Text.Encoding.UTF8.GetBytes("\r\n--" + boundary + "--");

string headerTemplate = "--" + boundary + "\r\nContent-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"\r\nContent-Type: {2}\r\n\r\n";

string header = string.Format(headerTemplate, "file", fileName, "application/octet-stream");

byte[] headerbytes = System.Text.Encoding.UTF8.GetBytes(header);

rs.Write(headerbytes, 0, headerbytes.Length);

using (var fileStream = new FileStream(file, FileMode.Open, FileAccess.Read))

{

var buffer = new byte[1024];

var bytesRead = 0;

while ((bytesRead = fileStream.Read(buffer, 0, buffer.Length)) != 0)

{

rs.Write(buffer, 0, bytesRead);

}

}

rs.Write(endBoundaryBytes, 0, endBoundaryBytes.Length);

rs.Flush();

rs.Position = 0;

byte[] tempBuffer = new byte[rs.Length];

rs.Read(tempBuffer, 0, tempBuffer.Length);

rs.Close();

MultipartFormDataContent formData = new MultipartFormDataContent();

formData.Headers.Remove("Content-Type");

formData.Headers.Add("Content-Type", "multipart/form-data; boundary=" + boundary);

ByteArrayContent bac = new ByteArrayContent(tempBuffer);

formData.Add(bac);

HttpRequestMessage req = new HttpRequestMessage(HttpMethod.Post, " /ws-api/v1/files?token=" + token);

req.Content = formData;

HttpResponseMessage response = await client.SendAsync(req);

var jsonResponse = await response.Content.ReadAsStringAsync();

I was adding the boundary at the wrong location. Boundary should be added at the Multipartformdatacontent level. This now works:

MultipartFormDataContent formData = new MultipartFormDataContent(boundary);

formData.Headers.Remove("Content-Type");

formData.Headers.TryAddWithoutValidation("Content-Type", "multipart/form-data; boundary=" + boundary);

ByteArrayContent bac = new ByteArrayContent(tempBuffer);

bac.Headers.ContentDisposition = new ContentDispositionHeaderValue("form-data");

bac.Headers.ContentDisposition.Name = "\"file\"";

bac.Headers.ContentDisposition.FileName = "\"" + file + "\"";

bac.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");

formData.Add(bac);

HttpRequestMessage req = new HttpRequestMessage(HttpMethod.Post, " /ws-api/v1/files?token=" + token);

req.Content = formData;