Represents a collection of trigger actions that can be individually accessed by index.
Despite the name of this collection, the items contained in the collection are not "TriggerAction" objects. Instead, they are BeginStoryboard objects.
TriggerActionCollection defines no methods or properties beyond the basic Collection methods and properties. Methods such as Add or GetItem will expect or return objects that are of type BeginStoryboard.
The XAML syntax for properties that use a TriggerActionCollection is an example of implicit collection syntax, in which you can omit an actual TriggerActionCollection object element, as well as the <EventTrigger.Actions> property element. Instead, you generally include one or more BeginStoryboard elements as child elements of an EventTrigger object.