public sealed class Calculator : IBackgroundTask{private BackgroundTaskDeferral backgroundTaskDeferral;private AppServiceConnection appServiceConnection;public void Run(IBackgroundTaskInstance taskInstance){this.backgroundTaskDeferral = taskInstance.GetDeferral();var details = taskInstance.TriggerDetails as AppServiceTriggerDetails;appServiceConnection = details.AppServiceConnection;appServiceConnection.RequestReceived += OnRequestReceived;taskInstance.Canceled += OnTaskCanceled;}private async void OnRequestReceived(AppServiceConnection sender, AppServiceRequestReceivedEventArgs args){var messageDeferral = args.GetDeferral();ValueSet message = args.Request.Message;ValueSet returnData = new ValueSet();string command = message["Command"] as string;      //Add, Subtract, Multiply, Divideint? firstNumber = message["Input1"] as int?;int? secondNumber = message["Input2"] as int?;int? result = 0;if (firstNumber.HasValue && secondNumber.HasValue){switch (command){case "Add":{result = firstNumber + secondNumber;returnData.Add("Result", result.ToString());returnData.Add("Status", "Complete");break;}case "Subtract":{result = firstNumber - secondNumber;returnData.Add("Result", result.ToString());returnData.Add("Status", "Complete");break;}case "Multiply":{result = firstNumber * secondNumber;returnData.Add("Result", result.ToString());returnData.Add("Status", "Complete");break;}case "Divide":{result = firstNumber / secondNumber;returnData.Add("Result", result.ToString());returnData.Add("Status", "Complete");break;}default:{returnData.Add("Status", "Fail: unknown command");break;}}}await args.Request.SendResponseAsync(returnData);messageDeferral.Complete();}private void OnTaskCanceled(IBackgroundTaskInstance sender, BackgroundTaskCancellationReason reason){if (this.backgroundTaskDeferral != null){this.backgroundTaskDeferral.Complete();}}}

public sealed partial class MainPage : Page{private AppServiceConnection calculatorService;public MainPage(){this.InitializeComponent();}private async void button_Click(object sender, RoutedEventArgs e){//Add the connectionif (calculatorService == null){calculatorService = new AppServiceConnection();calculatorService.AppServiceName = "CalculatorService1";calculatorService.PackageFamilyName = "83da5395-2473-49fb-b361-37072e87e9b9_xe3s0d4n4696a";var status = await calculatorService.OpenAsync();if (status != AppServiceConnectionStatus.Success){Result.Content = "Failed to connect";return;}}//Call the serviceint num1 = int.Parse(InputtextBox1.Text);int num2 = int.Parse(InputtextBox2.Text);var message = new ValueSet();message.Add("Command", Operation.SelectionBoxItem);message.Add("Input1", num1);message.Add("Input2", num2);AppServiceResponse response = await calculatorService.SendMessageAsync(message);string result = "";if (response.Status == AppServiceResponseStatus.Success){//Get the data that the service sentif (response.Message["Status"] as string == "Complete"){result = response.Message["Result"] as string;}}message.Clear();ResulttextBlock.Text = result;}}