Xamarin ListView not appearing with DateTime Binding

Question

there are many similar issues on SO, but I haven't yet found a solution that works for me. I have a listview that does not appear at all when bound to a class member's List. I have many working bindings, I just can't figure out what I'm doing wrong with this one. My listview XAML:

<ListView ItemsSource="{Binding DisplayTimecard.Days}"
                  SelectedItem="{Binding SelectedItem}">
            <ListView.Behaviors>
            <ioc:EventToCommandBehavior EventName="ItemTapped" 
                                      Command="{Binding ClickedDateCommand}"
                                      EventArgsConverter="{StaticResource ItemTappedEventArgsConverter}" />
            </ListView.Behaviors>
            <ListView.ItemTemplate>
                <DataTemplate>
                    <ViewCell>
                        <StackLayout Orientation="Vertical">
                            <StackLayout Orientation="Horizontal">
                                <Label Text="{Binding Path=Date, StringFormat=dd-MM-yyyy}"/>
                            </StackLayout>
                        </StackLayout>
                    </ViewCell>
                </DataTemplate>
            </ListView.ItemTemplate>
        </ListView>

and my ViewModel's OnNavigatedTo, where the data is loaded into my member list:

 public async override void OnNavigatedTo(INavigationParameters parameters)
        {
            PayPeriodsList = PayPeriods;
            RaisePropertyChanged("PayPeriodsList");
            SelectedPayPeriod = parameters["payperiod"] as PayPeriod;
            RaisePropertyChanged("SelectedPayPeriod");
            DisplayTimecard = SelectedPayPeriod.Timecards.First(x => x.EmployeesID == SelectedEmployee.EmployeeID);
            RaisePropertyChanged("DisplayTimecard");
            SetDisplayDates();

            if (SelectedEmployee != null)
            {
                UserName = "User: " + SelectedEmployee.EmployeeUsername;
                RaisePropertyChanged(UserName);
            }
        }

The method called that set's the dates in the List:

 public void SetDisplayDates()
        {
            for (var date = SelectedPayPeriod.StartDate; date <= SelectedPayPeriod.EndDate; date = date.AddDays(1))
            {
                DisplayTimecard.Days.Add(date);//List<DateTime> named in ListView's ItemsSource
            }
            RaisePropertyChanged("DisplayTimecard.Days");
        }

and finally my binding in viewmodel:

private Timecard _displayTimecard;
        public Timecard DisplayTimecard
        {
            get { return _displayTimecard; }
            set
            {
                SetProperty(ref _displayTimecard, value);
            }
        }

I've searched through many existing questions, but I have not found a solution that works for me. If anyone could shed some light on this issue, or point me to an existing question, i would really appreciate it.

Answer 1

OK - well I finally figured out what I was doing wrong, or at least what works now. From MS Docs:

If you want the ListView to automatically update as items are added, removed and changed in the underlying list, you'll need to use an ObservableCollection.

So, I changed my List to an observable Collection:

 public ObservableCollection<DateTime> Dates
        {
            get { return _dates; }
            set { SetProperty(ref _dates, value); }
        }

And I changed my Xaml binding syntax as well:

<ListView ItemsSource="{Binding Dates}"
                  SelectedItem="{Binding SelectedItem}">
            <ListView.Behaviors>
            <ioc:EventToCommandBehavior EventName="ItemTapped" 
                                      Command="{Binding ClickedDateCommand}"
                                      EventArgsConverter="{StaticResource ItemTappedEventArgsConverter}" />
            </ListView.Behaviors>
            <ListView.ItemTemplate>
                <DataTemplate>
                    <ViewCell>
                        <StackLayout Orientation="Vertical">
                            <StackLayout Orientation="Horizontal">
                                <Label Text="{Binding Date, StringFormat='{0:dd-MM-yyyy}'}"/>
                            </StackLayout>
                        </StackLayout>
                    </ViewCell>
                </DataTemplate>
            </ListView.ItemTemplate>
        </ListView>

I hope that my struggles might help someone, someday.