private async void Login() { if (CheckUserName()) { if (applicationService.IsConnected()) { Page HomePage = new HomeView(); UserManger usermanger = new UserManger(); int userId = await usermanger.AddUser(username); Task.WaitAll(); applicationService.AddAppProperty <string>("UserName", username); applicationService.AddAppProperty <int>("UserId", userId); await pageService.PushAsync(HomePage, () => { MessagingCenter.Send <LoginViewModel>(this, "SyncApplication"); }); } else { await pageService.DisplayAlert("Network", "Please turn on internet connectivity", "Ok"); } } else { await pageService.DisplayAlert("Invalid User Name", "User Name Must Not Contain Any Spaces Or Special Characters.", "Ok"); } }