I have a WebApi service handling an upload from a simple form, like this one:
However, I can't figure out how to simulate the same post using the HttpClient API. The FormUrlEncodedContent bit is simple enough, but how do I add the file contents with the name to the post?
After much trial and error, here's code that actually works:
using (var client = new HttpClient()) { using (var content = new MultipartFormDataContent()) { var values = new[] { new KeyValuePair("Foo", "Bar"), new KeyValuePair("More", "Less"), }; foreach (var keyValuePair in values) { content.Add(new StringContent(keyValuePair.Value), keyValuePair.Key); } var fileContent = new ByteArrayContent(System.IO.File.ReadAllBytes(fileName)); fileContent.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment") { FileName = "Foo.txt" }; content.Add(fileContent); var requestUri = "/api/action"; var result = client.PostAsync(requestUri, content).Result; } } You need to look for various subclasses of HttpContent.
You create a multiform http content and add various parts to it. In your case you have a byte array content and form url encoded along the lines of:
HttpClient c = new HttpClient(); var fileContent = new ByteArrayContent(new byte[100]); fileContent.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment") { FileName = "myFilename.txt" }; var formData = new FormUrlEncodedContent(new[] { new KeyValuePair("name", "ali"), new KeyValuePair("title", "ostad") }); MultipartContent content = new MultipartContent(); content.Add(formData); content.Add(fileContent); c.PostAsync(myUrl, content); Thank you @Michael Tepper for your answer.
I had to post attachments to MailGun (email provider) and I had to modify it slightly so it would accept my attachments.
var fileContent = new ByteArrayContent(System.IO.File.ReadAllBytes(fileName)); fileContent.Headers.ContentDisposition = new ContentDispositionHeaderValue("form-data") //Here for future reference. Thanks.