Observable Collection not updating when adding item - xaml

Question

I have tried everything but I cannot get to update my observable collection and be reflected in the UI. I have a method that adds a new entry to the collection that is bound to a CollectionViewSource which is bound to my collection. When I run the application Universal App I get the list correctly but if I add a value on click nothing gets reflected. Any suggestions?
The XAML looks like this:
<SemanticZoom>
<SemanticZoom.ZoomedInView>
<ListView IsHoldingEnabled="True"
ItemsSource="{Binding Mode=OneWay, Source={StaticResource MenuGroups}}"
ItemTemplate="{StaticResource MenuItemTemplate}"
ContinuumNavigationTransitionInfo.ExitElementContainer="True">
<ListView.GroupStyle>
<GroupStyle HidesIfEmpty="True" HeaderTemplate="{StaticResource MenuGroupHeaderTemplate}"/>
</ListView.GroupStyle>
</ListView>
</SemanticZoom.ZoomedInView>
<SemanticZoom.ZoomedOutView>
<GridView Background="Black"
ItemsSource="{Binding Source={StaticResource MenuGroups}, Path=CollectionGroups}"
ItemTemplate="{StaticResource MenuJumpTemplate}">
</GridView>
</SemanticZoom.ZoomedOutView>
</SemanticZoom>
Here is my code for the code behind:
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices.WindowsRuntime;
using Windows.Foundation;
using Windows.Foundation.Collections;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Controls.Primitives;
using Windows.UI.Xaml.Data;
using Windows.UI.Xaml.Input;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Navigation;
using TestWin.TestWinService;
using System.Globalization;
using System.Collections.ObjectModel;
using System.ComponentModel;
// The Blank Page item template is documented at http://go.microsoft.com/fwlink/?LinkId=402352&clcid=0x409
namespace TestWin
{
/// <summary>
/// An empty page that can be used on its own or navigated to within a Frame.
/// </summary>
public sealed partial class MenuPage : Page
{
#region Members
TestWinConnectionClient TestWinService;
ObservableCollection<Menu> ocMenuItems = null;
ObservableCollection<AlphaKeyGroup<Menu>> ocItemSource = null;
#endregion Members
#region Properties
public ObservableCollection<Menu> MenuItems
{
get
{
if (ocMenuItems == null)
{
ocMenuItems = new ObservableCollection<Menu>();
}
return ocMenuItems;
}
set
{
ocMenuItems = value;
OnPropertyChanged("MenuItems");
}
}
public ObservableCollection<AlphaKeyGroup<Menu>> ItemSource
{
get
{
if (ocItemSource == null)
{
ocItemSource = new ObservableCollection<AlphaKeyGroup<Menu>>((AlphaKeyGroup<Menu>.CreateGroups(MenuItems, CultureInfo.CurrentUICulture, s => s.MenuName, true)));
}
return ocItemSource;
}
set
{
ocItemSource = value;
OnPropertyChanged("ItemSource");
}
}
#endregion Properties
public MenuPage()
{
TestWinService = new TestWinConnectionClient();
this.InitializeComponent();
#region Events
this.Loaded += MenuPage_Loaded;
#endregion
}
private void MenuPage_Loaded(object sender, RoutedEventArgs e)
{
SetItemSource();
}
private async void SetItemSource()
{
MenuItems = await TestWinService.GetMenuEntriesAsync();
((CollectionViewSource)Resources["MenuGroups"]).Source = ItemSource;
}
private void TextBlock_Tapped(object sender, TappedRoutedEventArgs e)
{
Menu m = new Menu();
m.MenuName = "Test Entry";
m.SysRowID = Guid.NewGuid();
MenuItems.Add(m);
//this.Frame.Navigate(typeof(MenuPage));
}
public event PropertyChangedEventHandler PropertyChanged;
void OnPropertyChanged(string propertyName)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
}
}

Answer 1

If you add the new item to the MenuItems you also need to refresh the Source of CollectionViewSource.
Might be you have an ObservableCollection (ItemSource) that is not neccesary, you can take a look how I did it in Codeproject
and add for instance:
private async void Test()
{
await Task.Delay(5000);
for (int i = 0; i < 5; i++)
{
Favorites.Add(new Favorite()
{
Name = $"AAFriends {i}",
Category = new Category() { Name = "Friends" },
Uri = "http://www.expediteapps.com/blog/"
});
}
InitializeGrouping();
}
That refreshes only when I call the grouping again.