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Binding to ICollectionView doesn't display anything

It works when I bind directly to EventsSource but it doesn't when I change the binding to EventsView.
// EventsControl class
private bool Filter(object obj)
{
if (!(obj is Event #event)) return false;
if (string.IsNullOrEmpty(Location)) return true;
return true;
// return #event.Location == Location;
}
public static readonly DependencyProperty EventsSourceProperty = DependencyProperty.Register(
nameof(EventsSource), typeof(ObservableCollection<Event>), typeof(EventsControl), new PropertyMetadata(default(ObservableCollection<Event>), EventsSourceChanged));
public ObservableCollection<Event> EventsSource
{
get => (ObservableCollection<Event>)GetValue(EventsSourceProperty);
set => SetValue(EventsSourceProperty, value);
}
public ICollectionView EventsView { get; set; }
private static void EventsSourceChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
if (!(d is EventsControl eventsControl)) return;
var view = new CollectionViewSource { Source = e.NewValue }.View;
view.Filter += eventsControl.Filter;
eventsControl.EventsView = view;
//view.Refresh();
}
What could be wrong with this code?
I don't want to use a default view (
WPF CollectionViewSource Multiple Views? )

I made it a dependency property and it works. Not sure if that's the best way to solve it though.
public static readonly DependencyProperty EventsViewProperty = DependencyProperty.Register(
nameof(EventsView), typeof(ICollectionView), typeof(EventsControl), new PropertyMetadata(default(ICollectionView)));
public ICollectionView EventsView
{
get => (ICollectionView) GetValue(EventsViewProperty);
set => SetValue(EventsViewProperty, value);
}

WPF ComboBox Not updating on propertychanged event

I have a custom combobox in my WPF application and the combo box is not updating when my item source is updated after initial launch. The itemsSource is a custom observableDictionary. I've implemented INotifyPropertyChanged on my properties with my observableDictionary but it won't update. I've searched through every WPF propertychanged event not working on stack overflow and i'm looking for some assistance.
Custom Combobox Code:
<controls:MultiSelectComboBox Width="100" Height="30" Padding="0 10 0 0" Grid.Row="0" Grid.Column="1"
ItemsSource="{Binding Mode=TwoWay,
UpdateSourceTrigger=PropertyChanged,
ValidatesOnDataErrors=True,
Path=DataContext.OptionTeamMembersDictionary,
BindsDirectlyToSource=True,
RelativeSource={RelativeSource AncestorType={x:Type UserControl},Mode=FindAncestor}}"
SelectedItems="{Binding SelectedOptionTeamMembersDictionary, Mode=TwoWay}"
x:Name="TeamMemberDisplay"
ToolTip="{Binding Path=Text, RelativeSource={RelativeSource Self}}"/>
Properties and private variables:
private ObservableDictionary<string, object> _optionTeamMembersDictionary;
private ObservableDictionary<string, object> _selectedOptionTeamMembersDictionary;
public ObservableDictionary<string, object> OptionTeamMembersDictionary
{
get
{
return _optionTeamMembersDictionary;
}
set
{
_optionTeamMembersDictionary = value;
OnPropertyChanged("OptionTeamMembersDictionary");
}
}
public ObservableDictionary<string, object> SelectedOptionTeamMembersDictionary
{
get
{
return _selectedOptionTeamMembersDictionary;
}
set
{
_selectedOptionTeamMembersDictionary = value;
OnPropertyChanged("SelectedOptionTeamMembersDictionary");
}
}
I use a button to trigger a database pull which leads each row into an object and then populates the optionTeamMemberDictionary when it returns more then one row of data.
All of the above works when the data is loaded in my constructor but when its loaded after launch my comboboxes do not show the new data in the collection.
EDIT:
Code for the Custom ComboBox being used:
https://www.codeproject.com/Articles/563862/Multi-Select-ComboBox-in-WPF is the URL this came from. Some edits were made to implement an obserableDirctionary instead of normal dictionary
public partial class MultiSelectComboBox : UserControl
{
private ObservableCollection<Node> _nodeList;
public MultiSelectComboBox()
{
InitializeComponent();
_nodeList = new ObservableCollection<Node>();
}
#region Dependency Properties
public static readonly DependencyProperty ItemsSourceProperty =
DependencyProperty.Register("ItemsSource", typeof(ObservableDictionary<string, object>), typeof(MultiSelectComboBox), new FrameworkPropertyMetadata(null,
new PropertyChangedCallback(MultiSelectComboBox.OnItemsSourceChanged)));
public static readonly DependencyProperty SelectedItemsProperty =
DependencyProperty.Register("SelectedItems", typeof(ObservableDictionary<string, object>), typeof(MultiSelectComboBox), new FrameworkPropertyMetadata(null,
new PropertyChangedCallback(MultiSelectComboBox.OnSelectedItemsChanged)));
public static readonly DependencyProperty TextProperty =
DependencyProperty.Register("Text", typeof(string), typeof(MultiSelectComboBox), new UIPropertyMetadata(string.Empty));
public static readonly DependencyProperty DefaultTextProperty =
DependencyProperty.Register("DefaultText", typeof(string), typeof(MultiSelectComboBox), new UIPropertyMetadata(string.Empty));
public ObservableDictionary<string, object> ItemsSource
{
get { return (ObservableDictionary<string, object>)GetValue(ItemsSourceProperty); }
set
{
SetValue(ItemsSourceProperty, value);
}
}
public ObservableDictionary<string, object> SelectedItems
{
get { return (ObservableDictionary<string, object>)GetValue(SelectedItemsProperty); }
set
{
SetValue(SelectedItemsProperty, value);
}
}
public string Text
{
get { return (string)GetValue(TextProperty); }
set { SetValue(TextProperty, value); }
}
public string DefaultText
{
get { return (string)GetValue(DefaultTextProperty); }
set { SetValue(DefaultTextProperty, value); }
}
#endregion
#region Events
private static void OnItemsSourceChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
MultiSelectComboBox control = (MultiSelectComboBox)d;
control.DisplayInControl();
}
private static void OnSelectedItemsChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
MultiSelectComboBox control = (MultiSelectComboBox)d;
control.SelectNodes();
control.SetText();
}
private void CheckBox_Click(object sender, RoutedEventArgs e)
{
CheckBox clickedBox = (CheckBox)sender;
if (clickedBox.Content == "All")
{
if (clickedBox.IsChecked.Value)
{
foreach (Node node in _nodeList)
{
node.IsSelected = true;
}
}
else
{
foreach (Node node in _nodeList)
{
node.IsSelected = false;
}
}
}
else
{
int _selectedCount = 0;
foreach (Node s in _nodeList)
{
if (s.IsSelected && s.Title != "All")
_selectedCount++;
}
if (_selectedCount == _nodeList.Count - 1)
_nodeList.FirstOrDefault(i => i.Title == "All").IsSelected = true;
else
_nodeList.FirstOrDefault(i => i.Title == "All").IsSelected = false;
}
SetSelectedItems();
SetText();
}
#endregion
#region Methods
private void SelectNodes()
{
foreach (KeyValuePair<string, object> keyValue in SelectedItems)
{
Node node = _nodeList.FirstOrDefault(i => i.Title == keyValue.Key);
if (node != null)
node.IsSelected = true;
}
}
private void SetSelectedItems()
{
if (SelectedItems == null)
SelectedItems = new ObservableDictionary<string, object>();
SelectedItems.Clear();
foreach (Node node in _nodeList)
{
if (node.IsSelected && node.Title != "All")
{
if (this.ItemsSource.Count > 0)
SelectedItems.Add(node.Title, this.ItemsSource[node.Title]);
}
}
}
private void DisplayInControl()
{
_nodeList.Clear();
if (this.ItemsSource.Count > 0)
_nodeList.Add(new Node("All"));
foreach (KeyValuePair<string, object> keyValue in this.ItemsSource)
{
Node node = new Node(keyValue.Key);
_nodeList.Add(node);
}
MultiSelectCombo.ItemsSource = _nodeList;
}
private void SetText()
{
if (this.SelectedItems != null)
{
StringBuilder displayText = new StringBuilder();
foreach (Node s in _nodeList)
{
if (s.IsSelected == true && s.Title == "All")
{
displayText = new StringBuilder();
displayText.Append("All");
break;
}
else if (s.IsSelected == true && s.Title != "All")
{
displayText.Append(s.Title);
displayText.Append(',');
}
}
this.Text = displayText.ToString().TrimEnd(new char[] { ',' });
}
// set DefaultText if nothing else selected
if (string.IsNullOrEmpty(this.Text))
{
this.Text = this.DefaultText;
}
}
#endregion
}
public class Node : INotifyPropertyChanged
{
private string _title;
private bool _isSelected;
#region ctor
public Node(string title)
{
Title = title;
}
#endregion
#region Properties
public string Title
{
get
{
return _title;
}
set
{
_title = value;
NotifyPropertyChanged("Title");
}
}
public bool IsSelected
{
get
{
return _isSelected;
}
set
{
_isSelected = value;
NotifyPropertyChanged("IsSelected");
}
}
#endregion
public event PropertyChangedEventHandler PropertyChanged;
public void NotifyPropertyChanged(string propertyName)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
}

After much troubleshooting i was able to figure out an answer for this. onItemsSourceChanged was not firing after the control was instantiated so it never got updates made after initial launch of the application. I edited the OnItemsSourceChanged Function on the MultiFunctionComboBox to the below so it would fire on a changed event and it is working as expected now.
private static void OnItemsSourceChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
MultiSelectComboBox control = (MultiSelectComboBox)d;
var action = new NotifyCollectionChangedEventHandler(
(o, args) =>
{
MultiSelectComboBox c = (MultiSelectComboBox)d;
c?.DisplayInControl();
});
if (e.OldValue != null)
{
var sourceCollection = (ObservableDictionary<string, object>)e.OldValue;
sourceCollection.CollectionChanged -= action;
}
if (e.NewValue != null)
{
var sourceCollection = (ObservableDictionary<string, object>)e.NewValue;
sourceCollection.CollectionChanged += action;
}
control.DisplayInControl();
}

Why can't I reflect a list box choice in a text box in WPF?

I'm new to WPF and I'm having some trouble with my existing setup to get the list box selected item to appear in the text box.
The picture here represents the issue. I typed "12 HOUR" in the text box, which then filters the listbox to those items with "12 HOUR" anywhere in the string. But when I click "12 Hour Nasal" in the list box, I now want to reflect that choice back in the text box:
http://i.imgur.com/ZCYAolT.png
Here is my XAML for the user control containing the listbox and textbox:
<UserControl x:Class="SCM_AllergyRecModule.SearchAndSelectView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
mc:Ignorable="d">
<StackPanel Width="300">
<TextBox x:Name="Filter" Text="{Binding Path=Filter, UpdateSourceTrigger=PropertyChanged}"/>
<ListBox Width ="300" Height="50" x:Name="ListBoxControl"
ItemsSource="{Binding Path=Allergens}"
SelectedItem="{Binding Path=SelectedAllergen}">
</ListBox>
</StackPanel>
And here is the ViewModel:
namespace SCM_AllergyRecModule
{
public class SearchAndSelectViewModel
{
private ICollectionView allergens;
private string selectedAllergen;
private string filter = "";
public string Filter
{
get
{
return this.filter.ToUpperInvariant();
}
set
{
if (this.filter != value)
{
this.filter = value;
this.Allergens.Refresh();
}
}
}
private bool ContainsFilter(object item)
{
var product = item as string;
if (product == null)
{
return false;
}
if (string.IsNullOrEmpty(this.Filter))
{
return true;
}
if (product.ToUpperInvariant().Contains(this.Filter))
{
return true;
}
return false;
}
public SearchAndSelectViewModel()
{
var cvs = new CollectionViewSource();
cvs.Source = MainWindow.scmAllergens;
this.allergens = cvs.View;
this.allergens.Filter = ContainsFilter;
}
public ICollectionView Allergens
{
get
{
return this.allergens;
}
}
public string SelectedAllergen
{
get
{
return this.selectedAllergen;
}
set
{
if (this.selectedAllergen != value)
{
this.selectedAllergen = value;
}
}
}
}
}
Update 1
I added the INotifyPropertyChanged interface to my class and have it being raised on SelectedAllergen in the setter. I added an event handler called SearchAndSelectViewModel_PropertyChanged to handle the SelectedAllergen property changing and set it in the constructor.
Now when I click an item in the listbox, I do see it setting the Filter to the SelectedItem and the list filters to that item so nothing else shows. But still, the text box text is not changing? See screenshot below. This is after I typed in "PEAN" in the textbox, then the listbox filtered to two choices, and I chose "PEANUTS (FOOD)", which then refiltered the list box to just show that choice but didn't set the text box to "PEANUTS (FOOD)":
http://imgur.com/dNxuVI5
Updated ViewModel
public class SearchAndSelectViewModel : INotifyPropertyChanged
{
private ICollectionView allergens;
private string selectedAllergen;
private string filter;
public string Filter
{
get
{
return this.filter.ToUpperInvariant();
}
set
{
if (this.filter != value)
{
this.filter = value;
this.Allergens.Refresh();
}
}
}
private bool ContainsFilter(object item)
{
var product = item as string;
if (product == null)
{
return false;
}
if (string.IsNullOrEmpty(this.Filter))
{
return true;
}
if (product.ToUpperInvariant().Contains(this.Filter))
{
return true;
}
return false;
}
private void SearchAndSelectViewModel_PropertyChanged(object sender, PropertyChangedEventArgs e)
{
switch (e.PropertyName)
{
case "SelectedAllergen":
this.Filter = this.SelectedAllergen;
break;
}
}
public SearchAndSelectViewModel()
{
filter = "";
var cvs = new CollectionViewSource();
cvs.Source = MainWindow.scmAllergens;
this.allergens = cvs.View;
this.allergens.Filter = ContainsFilter;
this.PropertyChanged += SearchAndSelectViewModel_PropertyChanged;
}
public ICollectionView Allergens
{
get
{
return this.allergens;
}
}
public string SelectedAllergen
{
get
{
return this.selectedAllergen;
}
set
{
if (this.selectedAllergen != value && value != null)
{
this.selectedAllergen = value;
OnPropertyChanged("SelectedAllergen");
}
}
}
// INotifyPropertyChanged implementation
public event PropertyChangedEventHandler PropertyChanged;
public void OnPropertyChanged(string propertyName)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (handler != null)
{
handler(this, new PropertyChangedEventArgs(propertyName));
}
}
}

You need to implement the INotifyPropertyChanged interface and you can raise it in your property setter. Since you are also binding your TextBox to the Filter property you need to set the Filter property when your SelectedAllergen changes.
INotifyPropertyChanged example:
public class MyViewModel : INotifyPropertyChanged
{
//...
private int myProperty = 0;
public int MyProperty
{
get { return myProperty; }
set
{
myProperty = value;
// Raise the property changed notification
OnPropertyChanged("MyProperty");
}
}
// INotifyPropertyChanged implementation
public event PropertyChangedEventHandler PropertyChanged;
public void OnPropertyChanged(string propertyName)
{
PropertyChangedEventHandler handler = PropertyChanged;
if(handler != null)
{
handler(this, new PropertyChangedEventArgs(propertyName));
}
}
}

why my SelectedItems dependency property always returns null to bound property

I created a UserControl1 that wraps a DataGrid (this is simplified for test purposes, the real scenario involves a third-party control but the issue is the same). The UserControl1 is used in the MainWindow of the test app like so:
<test:UserControl1 ItemsSource="{Binding People,Mode=OneWay,ElementName=Self}"
SelectedItems="{Binding SelectedPeople, Mode=TwoWay, ElementName=Self}"/>
Everything works as expected except that when a row is selected in the DataGrid, the SelectedPeople property is always set to null.
The row selection flow is roughly: UserControl1.DataGrid -> UserControl1.DataGrid_OnSelectionChanged -> UserControl1.SelectedItems -> MainWindow.SelectedPeople
Debugging shows the IList with the selected item from the DataGrid is being passed to the SetValue call of the SelectedItems dependency property. But when the SelectedPeople setter is subsequently called (as part of the binding process) the value passed to it is always null.
Here's the relevant UserControl1 XAML:
<Grid>
<DataGrid x:Name="dataGrid" SelectionChanged="DataGrid_OnSelectionChanged" />
</Grid>
In the code-behind of UserControl1 are the following definitions for the SelectedItems dependency properties and the DataGrid SelectionChanged handler:
public static readonly DependencyProperty SelectedItemsProperty = DependencyProperty.Register("SelectedItems", typeof(IList), typeof(UserControl1), new FrameworkPropertyMetadata(null, FrameworkPropertyMetadataOptions.BindsTwoWayByDefault, OnSelectedItemsChanged));
public IList SelectedItems
{
get { return (IList)GetValue(SelectedItemsProperty); }
set
{
SetValue(SelectedItemsProperty, value);
}
}
private bool _isUpdatingSelectedItems;
private static void OnSelectedItemsChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
var ctrl = d as UserControl1;
if ((ctrl != null) && !ctrl._isUpdatingSelectedItems)
{
ctrl._isUpdatingSelectedItems = true;
try
{
ctrl.dataGrid.SelectedItems.Clear();
var selectedItems = e.NewValue as IList;
if (selectedItems != null)
{
var validSelectedItems = selectedItems.Cast<object>().Where(item => ctrl.ItemsSource.Contains(item) && !ctrl.dataGrid.SelectedItems.Contains(item)).ToList();
validSelectedItems.ForEach(item => ctrl.dataGrid.SelectedItems.Add(item));
}
}
finally
{
ctrl._isUpdatingSelectedItems = false;
}
}
}
private void DataGrid_OnSelectionChanged(object sender, SelectionChangedEventArgs e)
{
if (!_isUpdatingSelectedItems && sender is DataGrid)
{
_isUpdatingSelectedItems = true;
try
{
var x = dataGrid.SelectedItems;
SelectedItems = new List<object>(x.Cast<object>());
}
finally
{
_isUpdatingSelectedItems = false;
}
}
}
Here is definition of SomePeople from MainWindow code-behind:
private ObservableCollection<Person> _selectedPeople;
public ObservableCollection<Person> SelectedPeople
{
get { return _selectedPeople; }
set { SetProperty(ref _selectedPeople, value); }
}
public class Person
{
public Person(string first, string last)
{
First = first;
Last = last;
}
public string First { get; set; }
public string Last { get; set; }
}

I faced the same problem, i dont know reason, but i resolved it like this:
1) DP
public static readonly DependencyProperty SelectedItemsProperty = DependencyProperty.Register("SelectedItems", typeof(object), typeof(UserControl1),
new FrameworkPropertyMetadata(null, FrameworkPropertyMetadataOptions.BindsTwoWayByDefault, OnSelectedItemsChanged));
public object SelectedItems
{
get { return (object) GetValue(SelectedItemsProperty); }
set { SetValue(SelectedItemsProperty, value); }
}
2) Grid event
private void DataGrid_OnSelectionChanged(object sender, SelectionChangedEventArgs e)
{
var SelectedItemsCasted = SelectedItems as IList<object>;
if (SelectedItemsCasted == null)
return;
foreach (object addedItem in e.AddedItems)
{
SelectedItemsCasted.Add(addedItem);
}
foreach (object removedItem in e.RemovedItems)
{
SelectedItemsCasted.Remove(removedItem);
}
}
3) In UC which contain UserControl1
Property:
public IList<object> SelectedPeople { get; set; }
Constructor:
public MainViewModel()
{
SelectedPeople = new List<object>();
}

I know this is a super old post- but after digging through this, and a few other posts which address this issue, I couldn't find a complete working solution. So with the concept from this post I am doing that.
I've also created a GitHub repo with the complete demo project which contains more comments and explanation of the logic than this post. MultiSelectDemo
I was able to create an AttachedProperty (with some AttachedBehavour logic as well to set up the SelectionChanged handler).
MultipleSelectedItemsBehaviour
public class MultipleSelectedItemsBehaviour
{
public static readonly DependencyProperty MultipleSelectedItemsProperty =
DependencyProperty.RegisterAttached("MultipleSelectedItems", typeof(IList), typeof(MultipleSelectedItemsBehaviour),
new FrameworkPropertyMetadata(null, FrameworkPropertyMetadataOptions.BindsTwoWayByDefault, MultipleSelectedItemsChangedCallback));
public static IList GetMultipleSelectedItems(DependencyObject d) => (IList)d.GetValue(MultipleSelectedItemsProperty);
public static void SetMultipleSelectedItems(DependencyObject d, IList value) => d.SetValue(MultipleSelectedItemsProperty, value);
public static void MultipleSelectedItemsChangedCallback(object sender, DependencyPropertyChangedEventArgs e)
{
if (sender is DataGrid dataGrid)
{
if (e.NewValue == null)
{
dataGrid.SelectionChanged -= DataGrid_SelectionChanged;
}
else
{
dataGrid.SelectionChanged += DataGrid_SelectionChanged;
}
}
}
private static void DataGrid_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
if (sender is DataGrid dataGrid)
{
var selectedItems = GetMultipleSelectedItems(dataGrid);
if (selectedItems == null) return;
foreach (var item in e.AddedItems)
{
try
{
selectedItems.Add(item);
}
catch (ArgumentException)
{
}
}
foreach (var item in e.RemovedItems)
{
selectedItems.Remove(item);
}
}
}
}
To use it, one critical thing within the view model, is that the view model collection must be initialized so that the attached property/behaviour sets up the SelectionChanged handler. In this example I've done that in the VM constructor.
public MainWindowViewModel()
{
MySelectedItems = new ObservableCollection<MyItem>();
}
private ObservableCollection<MyItem> _myItems;
public ObservableCollection<MyItem> MyItems
{
get => _myItems;
set => Set(ref _myItems, value);
}
private ObservableCollection<MyItem> _mySelectedItems;
public ObservableCollection<MyItem> MySelectedItems
{
get => _mySelectedItems;
set
{
// Remove existing handler if there is already an assignment made (aka the property is not null).
if (MySelectedItems != null)
{
MySelectedItems.CollectionChanged -= MySelectedItems_CollectionChanged;
}
Set(ref _mySelectedItems, value);
// Assign the collection changed handler if you need to know when items were added/removed from the collection.
if (MySelectedItems != null)
{
MySelectedItems.CollectionChanged += MySelectedItems_CollectionChanged;
}
}
}
private int _selectionCount;
public int SelectionCount
{
get => _selectionCount;
set => Set(ref _selectionCount, value);
}
private void MySelectedItems_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
// Do whatever you want once the items are added or removed.
SelectionCount = MySelectedItems != null ? MySelectedItems.Count : 0;
}
And finally to use it in the XAML
<DataGrid Grid.Row="0"
ItemsSource="{Binding MyItems}"
local:MultipleSelectedItemsBehaviour.MultipleSelectedItems="{Binding MySelectedItems}" >
</DataGrid>

Button Command get not fired

I have a strange situation.
I working on an App for WINRT and have some problems with a command binding. This is the part of the xaml:
<control:ItemsHub ItemsSource="{Binding Categories}">
<control:ItemsHub.SectionHeaderTemplate>
<DataTemplate>
<Button Command="{Binding CategoryNavigationCommand}" Margin="5,0,0,10" Content="{Binding Header}"/>
</DataTemplate>
</control:ItemsHub.SectionHeaderTemplate>
</control:ItemsHub>
This is my ViewModel:
public CategorySectionViewModel(IRecipeService recipeService, INavigationService navigationService, RecipeTreeItemDto treeItem)
{
...
CategoryNavigationCommand = new DelegateCommand(NavigateToCategory);
...
}
private string _header;
public string Header
{
get { return _header; }
set { SetProperty(ref _header, value); }
}
public DelegateCommand CategoryNavigationCommand { get; private set; }
private void NavigateToCategory()
{
_navigationService.Navigate("CategoryHub", _recipeTreeItemDto.NodePath);
}
I don't get any binding errors in the output window and also the "Header" gets shown in the Button. But the Command won't get fired wenn i click on it! What i'm doing wrong?
Maybe it is because i created a custom HubControl. With this control i'm able to attach an ItemSource and ItemTemplate for the HubSection-Header and the HubSection-Content. Maybe because of this some bindings getting lost?
Here is my custom hub control:
public class ItemsHub : Hub
{
public DataTemplate ItemTemplate
{
get { return (DataTemplate)GetValue(ItemTemplateProperty); }
set { SetValue(ItemTemplateProperty, value); }
}
public IList ItemsSource
{
get { return (IList)GetValue(ItemsSourceProperty); }
set { SetValue(ItemsSourceProperty, value); }
}
public HubSection SpotlightSection
{
get { return (HubSection)GetValue(SpotlightSectionProperty); }
set { SetValue(SpotlightSectionProperty, value); }
}
public DataTemplate SectionHeaderTemplate
{
get { return (DataTemplate)GetValue(SectionHeaderTemplateProperty); }
set { SetValue(SectionHeaderTemplateProperty, value); }
}
public static readonly DependencyProperty ItemTemplateProperty =
DependencyProperty.Register("ItemTemplate", typeof(DataTemplate), typeof(ItemsHub), new PropertyMetadata(null, ItemTemplateChanged));
public static readonly DependencyProperty ItemsSourceProperty =
DependencyProperty.Register("ItemsSource", typeof(IList), typeof(ItemsHub), new PropertyMetadata(null, ItemsSourceChanged));
public static readonly DependencyProperty SpotlightSectionProperty =
DependencyProperty.Register("SpotlightSection", typeof(HubSection), typeof(ItemsHub), new PropertyMetadata(default(HubSection), SpotlightSectionChanged));
public static readonly DependencyProperty SectionHeaderTemplateProperty =
DependencyProperty.Register("SectionHeaderTemplate", typeof(DataTemplate), typeof(ItemsHub), new PropertyMetadata(default(DataTemplate), HeaderTemplateChanged));
private static void SpotlightSectionChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
ItemsHub hub = d as ItemsHub;
if (hub != null)
{
bool hubContainsSpotLight = hub.Sections.Contains(hub.SpotlightSection);
if (hub.SpotlightSection != null && !hubContainsSpotLight)
{
hub.Sections.Add(hub.SpotlightSection);
}
if (hub.SpotlightSection == null && hubContainsSpotLight)
{
hub.Sections.Remove(hub.SpotlightSection);
}
}
}
private static void HeaderTemplateChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
ItemsHub hub = d as ItemsHub;
if (hub != null)
{
DataTemplate template = e.NewValue as DataTemplate;
if (template != null)
{
// Apply template
foreach (var section in hub.Sections.Except(new List<HubSection> { hub.SpotlightSection }))
{
section.HeaderTemplate = template;
}
}
}
}
private static void ItemTemplateChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
ItemsHub hub = d as ItemsHub;
if (hub != null)
{
DataTemplate template = e.NewValue as DataTemplate;
if (template != null)
{
// Apply template
foreach (var section in hub.Sections.Except(new List<HubSection> { hub.SpotlightSection }))
{
section.ContentTemplate = template;
}
}
}
}
private static void ItemsSourceChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
ItemsHub hub = d as ItemsHub;
if (hub != null)
{
IList items = e.NewValue as IList;
if (items != null)
{
var spotLightSection = hub.SpotlightSection;
hub.Sections.Clear();
if (spotLightSection != null)
{
hub.Sections.Add(spotLightSection);
}
foreach (var item in items)
{
HubSection section = new HubSection();
section.DataContext = item;
section.Header = item;
DataTemplate headerTemplate = hub.SectionHeaderTemplate;
section.HeaderTemplate = headerTemplate;
DataTemplate contentTemplate = hub.ItemTemplate;
section.ContentTemplate = contentTemplate;
hub.Sections.Add(section);
}
}
}
}
}
Thanks for your help!

I found the solution! I don't know why but the section header of a hub control is not interactive by default! So i have to set the interactivity to true when i assign the itemsource in my custom ItemHub-Control.
Here is what i changed in the ItemsHub Control:
private static void ItemsSourceChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
ItemsHub hub = d as ItemsHub;
if (hub != null)
{
IList items = e.NewValue as IList;
if (items != null)
{
var spotLightSection = hub.SpotlightSection;
hub.Sections.Clear();
if (spotLightSection != null)
{
hub.Sections.Add(spotLightSection);
}
foreach (var item in items)
{
HubSection section = new HubSection();
DataTemplate headerTemplate = hub.SectionHeaderTemplate;
section.HeaderTemplate = headerTemplate;
DataTemplate contentTemplate = hub.ItemTemplate;
section.ContentTemplate = contentTemplate;
section.DataContext = item;
section.Header = item;
//This line fixed my problem.
section.IsHeaderInteractive = true;
hub.Sections.Add(section);
}
}
}

You can use following binding expression
Command="{Binding CategoryNavigationCommand,RelativeSource={RelativeSource AncestorType=XYX}}"
and XYZ is a control type in which you have placed ItemsHub