public TasksViewModel() { Title = "Tasks"; UserTasks = new ObservableCollection <UserTask>(); LoadItemsCommand = new Command(async() => ExecuteLoadItemsCommand()); EditItemCommand = new Command(async(item) => await EditItem(item)); DeleteItemCommand = new Command((item) => DeleteItem(item)); MessagingCenter.Subscribe <NewTaskPageViewModel, UserTask>(this, AppMessages.SaveUserTaskMessage, async(obj, item) => { var _item = item as UserTask; if (item != null) { bool result = await AppService.AddNewUserTask(_item); if (result) { UserTasks = new ObservableCollection <UserTask>(AppService.UserTasks); } } }); }