Checkbox not showing as checked inside ListView - wpf

Question

I have a checkbox inside a listview. The listview is bound to an observable collection. When I use the context menu to try to select all Checkboxes, they do not show as checked. What am I doing wrong?
<ListView Grid.Row="1" Grid.Column="0" ItemsSource="{Binding AvailableModels}"
HorizontalAlignment="Stretch" VerticalAlignment="Stretch"
SelectionMode="Extended">
<ListView.ContextMenu>
<ContextMenu>
<MenuItem Header="Select All Models" Command="{Binding
SelectAllModelsAction}" />
<MenuItem Header="Deselect All Models" Command="{Binding
DeselectAllModelsAction}" />
</ContextMenu>
</ListView.ContextMenu>
<ListView.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<CheckBox IsChecked="{Binding DataContext.IsSelected,
RelativeSource={RelativeSource
FindAncestor, AncestorType={x:Type
ListViewItem}}}" VerticalAlignment="Center" />
<Label Content="{Binding Name}" Margin="2,0,0,0" />
</StackPanel>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
ViewModel
public ObservableCollection<ListItems> AvailableModels
{
get
{
return this.availableModels;
}
set
{
this.availableModels = value;
this.NotifyPropertyChanged(m => m.AvailableModels);
}
}
Context Menu Action
private void SelectAllModels()
{
foreach (var model in this.AvailableModels)
{
model.IsSelected = true;
}
this.NotifyPropertyChanged(m => m.AvailableModels);
}
ListItems Object
public class ListItems
{
public string Name
{
get;
set;
}
public object Value
{
get;
set;
}
public bool IsSelected
{
get;
set;
}
}

Answer 1

ListItems isn't implementing INotifyPropertyChanged so changing IsSelected isn't updating the UI.
Calling NotifyPropertyChanged in SelectAllModels() is unnecessary since the collection itself isn't changed. The NotifyProperyChanged() call in the AvailableModels setter updates the UI when a new collection is set. And ObservableCollection will handle when the collection is modified (items added/removed). However changes to the properties within the ListItems does not update the UI unless they call NotifyPropertyChanged in the setters.