public static async Task <IEnumerable <FaceModel> > GetFacesAsync(byte[] byteData) { try { HttpClient client = new HttpClient(); client.DefaultRequestHeaders.Add(AzureApiConstants.SubscriptionKeyHeader, AzureApiConstants.SubscriptionKey); string uri = AzureApiConstants.UriBase + "?" + AzureApiConstants.DefaultRequestParameters; HttpResponseMessage response; using (ByteArrayContent content = new ByteArrayContent(byteData)) { content.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream"); response = await client.PostAsync(uri, content); } return(FaceModel.FromJson(await response.Content.ReadAsStringAsync())); } catch (Exception e) { Console.WriteLine("\n" + e.Message); } return(null); }