Requisição HTTP Basic Authorization com C#

gistfile1.cs

using (var client = new HttpClient())
{
    client.DefaultRequestHeaders.Add("Authorization", "Basic d2FsZHlyOjEyMw==");
    var strings = await client.GetAsync("/api/values");
    var strResult = await strings.Content.ReadAsStringAsync();

    var serializer = new JavaScriptSerializer();
    var result = serializer.Deserialize<string[]>(strResult);

    foreach (var s in result)
    {
        Console.WriteLine(s);
    }
}