private void Button1_Click_1(object sender, RoutedEventArgs e) { // Create the object var nativeObject = new WinRT_CPP.Class1(); // Call the synchronous method. val is an IList that // contains the results. var val = nativeObject.ComputeResult(0); StringBuilder result = new StringBuilder(); foreach (var v in val) { result.Append(v).Append(System.Environment.NewLine); } this.Result1.Text = result.ToString(); }