public SinglePageNavigationPage() { NavigationPage.SetHasNavigationBar(this, false); InitializeComponent(); Resources["ButtonStyle"] = Resources["answerStyle"]; Resources["FlagButtonStyle"] = Resources["flagDefaultStyle"]; // Set Title to zero-based instance of this class. int questionNumber = (count++) + 1; if ((bool)Application.Current.Properties["IsNewQuiz"]) { var subject = Application.Current.Properties["subject"] + ".json"; QuestionData.InitialiseQuestions(subject); Application.Current.Properties["IsNewQuiz"] = false; } IDictionary <string, object> properties = Application.Current.Properties; if (properties.ContainsKey("TimerStatus") && (string)properties["TimerStatus"] == "Started") { //timer has started } else { //reset QuestionData.GetQuestions.Reset(); _timerViewModel = new TimerViewModel(); _timerViewModel.IsVisiblePrevNavButton = true; //_timerViewModel.IsVisibleFinishButton = false; Application.Current.Properties["TimerStatus"] = "Started"; } var numberOfQuestions = QuestionData.GetQuestions.questions.Count; Title = "Q" + questionNumber + " of " + numberOfQuestions; BindingContext = _timerViewModel; }