private async void buttonUpload_Click(object sender, EventArgs e) { if ( FormImageUploadValidator.ValidRequiredTextBoxFields(errorProvider, textBoxRequestNumber, textBoxUserName) && FormImageUploadValidator.ValidateFileInputField(errorProvider, openFileDialog, buttonAddFile) && FormImageUploadValidator.ValidateRequestNumber(errorProvider, textBoxRequestNumber) ) { disableAllButtons(); var response = await HTTPUtility.PostData( ConfigurationManager.AppSettings["SurityRestAPIBaseURL"] + ConfigurationManager.AppSettings["ImageUploadEndpoint"], new { RequestNumber = textBoxRequestNumber.Text, UserName = textBoxUserName.Text, ImageName = openFileDialog.SafeFileName, ImageData = File.ReadAllBytes(openFileDialog.FileName) } ); if (response.StatusCode == HttpStatusCode.OK) { errorProvider.SetError(buttonUpload, string.Empty); showUploadSuccessText(); } else { errorProvider.SetError(buttonUpload, await response.Content.ReadAsStringAsync()); labelUploadSuccess.Text = string.Empty; } enableAllButtons(); } }