[Solved] ParentTileView returns nothing

[Trude]

I have this databound tileview declared (part of an itemscontrol):

<telerik:RadTileView  ItemContainerStyle="{StaticResource RadTileViewItemStyle1}"
                    IsSelectionEnabled="True" SelectionMode="Single" MaxRows="1" IsAnimationOptimized="True"
                    Loaded="TileView1_Loaded" PreviewTileSelectionChanged="TileView1_PreviewTileSelectionChanged"
                    MaximizeMode="Zero"/>

In the code behind I have:

Private Sub TileView1_Loaded(sender As System.Object, e As System.Windows.RoutedEventArgs)
    Dim _tv As RadTileView = sender

    _tv.ItemsSource = DirectCast(_tv.DataContext, main_data_tab).details_tab
    AddHandler _tv.ItemContainerGenerator.StatusChanged, AddressOf ItemContainerGenerator_StatusChanged

End Sub

Private Sub ItemContainerGenerator_StatusChanged(sender As Object, e As System.EventArgs)
    Dim _cg = TryCast(sender, Telerik.Windows.Controls.ItemContainerGenerator)

    If _cg IsNot Nothing And _cg.Status = Primitives.GeneratorStatus.ContainersGenerated Then
        Dim _tileview = DirectCast(_cg.ContainerFromIndex(0), RadTileViewItem).ParentTileView
        If _tv IsNot Nothing Then
            For Each _item In _tv.Items
                Dim _container As RadTileViewItem = _cg.ContainerFromItem(_item)
                If _container.Tag Is Nothing Then
                    AddHandler _container.MouseEnter, AddressOf RadTileViewItem_MouseEnter
                    _container.Tag = "Processed"
                End If
            Next
        End If
    End If
End Sub

So, when the tileview is loaded I set it's ItemsSource and subscribe to the ItemContainerGenerator.StatusChanged event. If I add an item to the ItemsSource the event fires and I need to find which tileview raised it (ParentTileView of ContainerFromIndex(0)). I do get a reference to the TileViewItem, but it's ParentTileView property is nothing. If I add a second item the ParentTileView is suddenly pointing to the correct tileview. Is this intentional? Is there another way to find which tileview raised the event?

[Zarko]

Hello Jorn,
This is expected behavior because when the StatusChanged event is fired with ContainersGenerated status all containers are already generated, but most of the properties of the last added container are still not set. There are two things you can do - if the ParentTileView property is null, you can get the parent RadTileView with the ParentOfType<T>() method like this:
 

Dim firstContainer = DirectCast(cg.ContainerFromIndex(0), RadTileViewItem)
Dim tileview = firstContainer.ParentTileView
If tileview Is Nothing Then
    tileview = firstContainer.ParentOfType(Of RadTileView)()
End If

If tileview IsNot Nothing Then
    For Each item As Object In tileview.Items
        Dim container As RadTileViewItem = TryCast(cg.ContainerFromItem(item), RadTileViewItem)
        If container.Tag Is Nothing Then
            container.MouseEnter += Me.container_MouseEnter
            container.Tag = "Processed"
        End If
    Next
End If

Or use a dispatcher to wait until the properties are set:

Me.Dispatcher.BeginInvoke(New Action(Function()
Dim tileview = DirectCast(cg.ContainerFromIndex(0), RadTileViewItem).ParentTileView
If tileview IsNot Nothing Then
    For Each item As Object In tileview.Items
        Dim container As RadTileViewItem = TryCast(cg.ContainerFromItem(item), RadTileViewItem)
        If container.Tag Is Nothing Then
            container.MouseEnter += Me.container_MouseEnter
            container.Tag = "Processed"
        End If
    Next
End If

End Function))

If you have more questions feel free to ask.

Greetings,
Zarko
the Telerik team

[Trude]

First method works great! Thanks!