client side is using MultipartFormDataContent with two part of data, one is a file, the other one is some metadata. In each 3 request, there will be 2 request failed due to FileData empty.
Client:
var client = new HttpClient(new WebRequestHandler());
using (var content = new MultipartFormDataContent())
{
var guid = Guid.NewGuid().ToString();
var tmpFileName = string.Format("{0}{1}", guid, Path.GetExtension(fileName));
var dataContent = new ByteArrayContent(data);
content.Add(dataContent, guid, tmpFileName);
var optionContent = new ByteArrayContent(optionData);
optionContent.Headers.ContentDisposition = new ContentDispositionHeaderValue("parameter") { Name = "optionsStr" };
content.Add(optionContent);
var response = client.PostAsync("http://test.com", content).Result;
}
Server:
[HttpPost]
public async Task<HttpResponseMessage> UploadDocument(string dataStr)
{
string rootPath = System.Web.HttpContext.Current.Server.MapPath("~/App_Data/Documents");
MultipartFormDataStreamProvider provider = new MultipartFormDataStreamProvider(rootPath);
await Request.Content.ReadAsMultipartAsync(provider);
if (provider.FileData == null || provider.FileData.Count == 0)
throw new Exception("There is no file in the current request of httpcontext.");
}
After sniffing using Wiresharks, found out the actual file data was misplaced in the preamble section of the multi-part structure:
error request:
correct request:
any clue what may cause such behavior?
