public async Task <ActionResult> FileUpload(HttpPostedFileBase file) { if (file == null) { return(RedirectToAction("Upload")); } var apiService = new FaceApiService(ConfigurationManager.AppSettings["FaceApiKey"]); byte[] resultImage = await apiService.UploadAndDetectFace(file); TempData["resultImageBase64"] = GetImageBase64String(resultImage); return(RedirectToAction("ViewFaces")); }