I have having issues with a storyboard that is complaining about being unfreezable. There are alot of links on google about this, however I am not sure from reading that information how I can achieve what I want. (ie pretty much just execute a custom command from IsMouseOver property change). I am using data templating to change my listview to look like the link I have provided in the information below:
My resource dictionary:
<DataSourceProviders:ServiceLocatorProvider ServiceType="{x:Type Interfaces:IGestureBuilderModuleController}" x:Key="GestureController"/>
<Converters:IsGestureBeingBuiltConverter x:Key="IsGestureBeingBuildConverter" />
My UI looks like:
<ListView.ItemContainerStyle>
<Style TargetType="{x:Type ListViewItem}">
<Style.Triggers>
<MultiDataTrigger>
<MultiDataTrigger.Conditions>
<Condition Binding="{Binding IsMouseOver}" Value="True" />
<Condition Binding="{Binding Path=CurrentGestureState, Converter={StaticResource IsGestureBeingBuildConverter}}" Value="True" />
</MultiDataTrigger.Conditions>
<!--TODO:Need to add a button to this control. Then use the buttons event to trigger command.-->
<MultiDataTrigger.ExitActions>
<BeginStoryboard>
<StoryBoard:CommandTimeline StoryBoard:CommandStoryboard.Command="{Binding Source={StaticResource ResourceKey=GestureController}, Path=AddToGestureCommand}" />
</BeginStoryboard>
</MultiDataTrigger.ExitActions>
</MultiDataTrigger>
</Style.Triggers>
</Style>
</ListView.ItemContainerStyle>
My converter looks like:
[ValueConversion(typeof(GestureState), typeof(bool))]
public class IsGestureBeingBuiltConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
return Equals(value, GestureState.BeingConstructed);
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
}
My GestureState Enum looks like:
public enum GestureState
{
Finished,
BeingConstructed
}
My Gesture controller/command looks like:
public class GestureBuilderModuleController : ModuleController, IGestureBuilderModuleController
{
public ICommand AddToGestureCommand
{
get { return new DelegateCommand<GestureBuilderViewModel>(viewModel => viewModel.AddToGesture = true); }
}
}
My viewmodel looks like:
public GestureableItemViewModel ItemBeingAdded { get; set; }
public virtual bool AddToGesture
{
get { return false; }
set
{
if (ItemBeingAdded == null) return;
if(CurrentGestureState != GestureState.BeingConstructed) return;
SelectedItems.Add(ItemBeingAdded);
}
}
The exception I am getting is:
InvalidOperation: Cannot freeze storyboard.
My UI looks LIKE this:
Current understanding:
I understand from reading that storyboards need to be freezable for quick access across threads where they are unfrozen.
My Question is how can I make my binding in a way that it is freezable OR achieve what I want using an alternate approach. My core problem is that I want to raise a custom command or event when mousing over a listitem when capturing a gesture.
You don't need Storyboard. In your Multidatatrigger, use a OneWayToTarget DataBinding to set a property in your ViewModel. That property's setter will be invoked when the trigger condition meets. In that setter you can call "this.AddToGesture = true".
