Using DefaultRequestHeaders sends requests twice?

Question

I have a WebAPI that sends BASIC authorization information as following.

var client = new HttlpClient();
client.BaseAddress = new Uri(GlobalConstants.LdapUri);
var contentType = new MediaTypeWithQualityHeaderValue("application/json");

client.DefaultRequestHeaders.Accept.Add(contentType);
client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Basic", Convert.ToBase64String(Encoding.ASCII.GetBytes(string.Format("{0}:{1}", userName, password))));
Task<HttpResponseMessage> results = client.GetAsync(GlobalConstants.FortressAPIUriDev);
var response = await results;

I've built this API using MVC Core 1.x and the receiving API is built using MVC5.

The problem is that this GetAsync sends two requests at the same time, and I have no clue how to resolve this. I've done some Googling myself to see if I can find a fix for this but so far no luck. Did anyone experience this problem and know how to resolve it?

Thank you very much in advance.

@PoulBak Thank you for your comment, but what other information should I provide? — A J, Sep 27 '18 at 22:03
Can it possibly be two requests from client at the same time? — Poul Bak, Sep 27 '18 at 22:04
Yes, I found a few postings talking about similar issues. Something like this: https://stackoverflow.com/questions/6338942/why-my-http-client-making-2-requests-when-i-specify-credentials — A J, Sep 27 '18 at 22:07
Then it's a different question. I suggest you post some JavaScript. — Poul Bak, Sep 27 '18 at 22:08

score 0 · Answer 1 · answered Sep 27 '18 at 23:03

Long story short, found a solution as follows:

using (var client = new HttpClient())
{
    var requestMessage = new HttpRequestMessage(HttpMethod.Get, GlobalConstants.LdapUri + GlobalConstants.FortressAPIUriDev);
    requestMessage.Headers.Authorization = new AuthenticationHeaderValue("Basic", Convert.ToBase64String(Encoding.ASCII.GetBytes(string.Format("{0}:{1}", userName, password))));
    var response = await client.SendAsync(requestMessage);
}

After replacing with this code, it is sending one request at a time. Found a hint at : Adding headers when using httpClient.GetAsync

Using DefaultRequestHeaders sends requests twice?

1 Answers1