Adding Http Headers to HttpClient

Question

I need to add http headers to the HttpClient before I send a request to a web service. How do I do that for an individual request (as opposed to on the HttpClient to all future requests)? I'm not sure if this is even possible.

var client = new HttpClient();
var task =
    client.GetAsync("http://www.someURI.com")
    .ContinueWith((taskwithmsg) =>
    {
        var response = taskwithmsg.Result;

        var jsonTask = response.Content.ReadAsAsync<JsonObject>();
        jsonTask.Wait();
        var jsonObject = jsonTask.Result;
    });
task.Wait();

Answer 1

Create a HttpRequestMessage, set the Method to GET, set your headers and then use SendAsync instead of GetAsync.

static HttpClient _client = new HttpClient();

using var request = new HttpRequestMessage() {
    RequestUri = new Uri("http://www.someURI.com"),
    Method = HttpMethod.Get,
};
request.Headers.Accept.Add(new MediaTypeWithQualityHeaderValue("text/plain"));
using var response = await client.SendAsync(request);
var jsonObject = await response.Content.ReadAsAsync<JsonObject>();

Answer 2

When it can be the same header for all requests or you dispose the client after each request you can use the DefaultRequestHeaders.Add option:

client.DefaultRequestHeaders.Add("apikey","xxxxxxxxx");