/// <summary>
/// Gets the TriggerCollection containing the triggers associated with the specified object.
/// </summary>
/// <param name="obj">The object from which to retrieve the triggers.</param>
/// <returns>A TriggerCollection containing the triggers associated with the specified object.</returns>
public static TriggerCollection GetTriggers(DependencyObject obj)
{
TriggerCollection triggerCollection = (TriggerCollection)obj.GetValue(Interaction.TriggersProperty);
if (triggerCollection == null)
{
triggerCollection = new TriggerCollection();
obj.SetValue(Interaction.TriggersProperty, triggerCollection);
}
return(triggerCollection);
}
/// <exception cref="InvalidOperationException">Cannot host the same TriggerCollection on more than one object at a time.</exception>
private static void OnTriggersChanged(DependencyObject obj, DependencyPropertyChangedEventArgs args)
{
TriggerCollection oldCollection = args.OldValue as TriggerCollection;
TriggerCollection newCollection = args.NewValue as TriggerCollection;
if (oldCollection != newCollection)
{
if (oldCollection != null && ((IAttachedObject)oldCollection).AssociatedObject != null)
{
oldCollection.Detach();
}
if (newCollection != null && obj != null)
{
if (((IAttachedObject)newCollection).AssociatedObject != null)
{
throw new InvalidOperationException("Error Message");
}
newCollection.Attach(obj);
}
}
}