Upload raw byte data with dotnet core HttpClient

Question

I am updating some old C# code to use HttpClient instead of WebClient. As part of this, I need to upload a byte array of a file to an api.

With WebClient, this worked perfectly fine

byte[] data = GetMyData();
using (var client = new WebClient())
{
    //set url, headers etc
    var r = client.UploadData(url, "PUT", data);
}

With HttpClient, I've tried various methods, such as

byte[] data = GetMyData();
using (var client = new HttpClient())
{
    //set url, headers etc
    var r = await client.PutAsync(url, new ByteArrayContent(data));
}

I've also tried different ways of using Multipart data that I found Googling around, but the server does not accept anything I've tried. I don't have a lot of documentation on the server API, I only know that the WebClient way has worked well for many years. Is there a way to recreate the WebClient.UploadData behavior with HttpClient?

Answer 1

Thanks to the commenters for putting me on the right track. The Content-Type headers were not being set correctly for the HttpClient way, by putting it on the actual content. code below.

byte[] data = GetMyData();
using (var client = new HttpClient())
{
    //set url, headers etc
    var content = new ByteArrayContent(data);
    content.Headers.ContentType = new MediaTypeWithQualityHeaderValue(contentType);
    var r = await client.PutAsync(url, content);
}