Question

In my project I have a WPF Listbox bound to an ObservableCollection. Every time I add a new item to the Collection the same item is added to the Listbox automaticly. To display the items in the Listbox I use a XAML Datatemplate.

What I want to do is animate an item once when it is added to the Collection/Listbox. Can this be done? As animation in the datatemplate maybe? I guess I need a trigger somehow to start this animate but what trigger is fired when a new item/datatemplate is added?

Answer 1

I think an event trigger for the FrameworkElement.Loaded routed event could work. For example:

<DataTemplate DataType='{x:Type l:Foo}'>     <Button x:Name='Button' Content='{Binding Path=Bar}'>         <Button.Background>             <SolidColorBrush x:Name='ButtonBrush' Color='Tan' />         </Button.Background>     </Button>     <DataTemplate.Triggers>         <EventTrigger RoutedEvent='FrameworkElement.Loaded' SourceName='Button'>             <BeginStoryboard>                 <Storyboard>                     <ColorAnimation Storyboard.TargetName='ButtonBrush' Storyboard.TargetProperty='Color' To='Red' />                 </Storyboard>             </BeginStoryboard>         </EventTrigger>     </DataTemplate.Triggers> </DataTemplate>