I have a WebApi service handling an upload from a simple form, like this one:
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<string, string>("Foo", "Bar"),
new KeyValuePair<string, string>("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<string, string>("name", "ali"),
new KeyValuePair<string, string>("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") //<- 'form-data' instead of 'attachment'
{
Name = "attachment", // <- included line...
FileName = "Foo.txt",
};
multipartFormDataContent.Add(fileContent);
Here for future reference. Thanks.