private async void Start_Click(object sender, RoutedEventArgs e)
        {
            Uri resourceAddress;

            // The value of 'AddressField' is set by the user and is therefore untrusted input. If we can't create a
            // valid, absolute URI, we'll notify the user about the incorrect input.
            if (!Helpers.TryGetUri(AddressField.Text, out resourceAddress))
            {
                rootPage.NotifyUser("Invalid URI.", NotifyType.ErrorMessage);
                return;
            }

            Helpers.ScenarioStarted(StartButton, CancelButton, OutputField);
            rootPage.NotifyUser("In progress", NotifyType.StatusMessage);

            try
            {
                IHttpContent jsonContent = new HttpJsonContent(JsonValue.Parse("{\"score\": 100, \"enabled\": false}"));

                HttpResponseMessage response = await httpClient.PostAsync(resourceAddress, jsonContent).AsTask(cts.Token);

                await Helpers.DisplayTextResultAsync(response, OutputField, cts.Token);

                rootPage.NotifyUser("Completed", NotifyType.StatusMessage);
            }
            catch (TaskCanceledException)
            {
                rootPage.NotifyUser("Request canceled.", NotifyType.ErrorMessage);
            }
            catch (Exception ex)
            {
                rootPage.NotifyUser("Error: " + ex.Message, NotifyType.ErrorMessage);
            }
            finally
            {
                Helpers.ScenarioCompleted(StartButton, CancelButton);
            }
        }
        private async void Start_Click(object sender, RoutedEventArgs e)
        {
            Uri resourceAddress;

            // The value of 'AddressField' is set by the user and is therefore untrusted input. If we can't create a
            // valid, absolute URI, we'll notify the user about the incorrect input.
            if (!Helpers.TryGetUri(AddressField.Text, out resourceAddress))
            {
                rootPage.NotifyUser("Invalid URI.", NotifyType.ErrorMessage);
                return;
            }

            Helpers.ScenarioStarted(StartButton, CancelButton, OutputField);
            rootPage.NotifyUser("In progress", NotifyType.StatusMessage);

            try
            {
                IHttpContent jsonContent = new HttpJsonContent(JsonValue.Parse("{\"score\": 100, \"enabled\": false}"));

                HttpResponseMessage response = await httpClient.PostAsync(resourceAddress, jsonContent).AsTask(cts.Token);

                await Helpers.DisplayTextResultAsync(response, OutputField, cts.Token);

                rootPage.NotifyUser("Completed", NotifyType.StatusMessage);
            }
            catch (TaskCanceledException)
            {
                rootPage.NotifyUser("Request canceled.", NotifyType.ErrorMessage);
            }
            catch (Exception ex)
            {
                rootPage.NotifyUser("Error: " + ex.Message, NotifyType.ErrorMessage);
            }
            finally
            {
                Helpers.ScenarioCompleted(StartButton, CancelButton);
            }
        }