Adding headers when using httpClient.GetAsync

问题

I'm implementing an API made by other colleagues with Apiary.io, in a Windows Store app project.

They show this example of a method I have to implement:

var baseAddress = new Uri("https://private-a8014-xxxxxx.apiary-mock.com/");

using (var httpClient = new HttpClient{ BaseAddress = baseAddress })
{
    using (var response = await httpClient.GetAsync("user/list{?organizationId}"))
    {
        string responseData = await response.Content.ReadAsStringAsync();
    }
}

In this and some other methods, I need to have a header with a token that I get before.

Here's an image of Postman (chrome extension) with the header I'm talking about:

How do I add that Authorization header to the request?

回答1:

When using GetAsync with the HttpClient you can add the authorization headers like so:

httpClient.DefaultRequestHeaders.Authorization 
                         = new AuthenticationHeaderValue("Bearer", "Your Oauth token");

This does add the authorization header for the lifetime of the HttpClient so is useful if you are hitting one site where the authorization header doesn't change.

Here is an detailed SO answer

回答2:

A later answer, but because no one gave this solution...

If you do not want to set the header on the HttpClient instance by adding it to the DefaultRequestHeaders, you could set headers per request.

But you will be obliged to use the SendAsync() method.

This is the right solution if you want to reuse the HttpClient -- which is a good practice for

performance and port exhaustion problems
doing something thread-safe
not sending the same headers every time

Use it like this:

using (var requestMessage =
            new HttpRequestMessage(HttpMethod.Get, "https://your.site.com"))
{
    requestMessage.Headers.Authorization =
        new AuthenticationHeaderValue("Bearer", your_token);
    httpClient.SendAsync(requestMessage);
}

回答3:

The accepted answer works but can got complicated when I wanted to try adding Accept headers. This is what I ended up with. It seems simpler to me so I think I'll stick with it in the future:

client.DefaultRequestHeaders.Add("Accept", "application/*+xml;version=5.1");
client.DefaultRequestHeaders.Add("Authorization", "Basic " + authstring);

回答4:

You can add whatever headers you need to the HttpClient.

Here is a nice tutorial about it.

This doesn't just reference to POST-requests, you can also use it for GET-requests.

回答5:

Following the greenhoorn's answer, you can use "Extensions" like this:

  public static class HttpClientExtensions
    {
        public static HttpClient AddTokenToHeader(this HttpClient cl, string token)
        {
            //int timeoutSec = 90;
            //cl.Timeout = new TimeSpan(0, 0, timeoutSec);
            string contentType = "application/json";
            cl.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue(contentType));
            cl.DefaultRequestHeaders.Add("Authorization", String.Format("Bearer {0}", token));
            var userAgent = "d-fens HttpClient";
            cl.DefaultRequestHeaders.Add("User-Agent", userAgent);
            return cl;
        }
    }

And use:

string _tokenUpdated = "TOKEN";
HttpClient _client;
_client.AddTokenToHeader(_tokenUpdated).GetAsync("/api/values")

来源：https://stackoverflow.com/questions/29801195/adding-headers-when-using-httpclient-getasync

标签

windows-runtime

windows-store-apps

dotnet-httpclient

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