Adds a TextEffect to the end of the collection.
Assembly: PresentationCore (in PresentationCore.dll)
Because TextEffect objects derive from Freezable, they are copied when they are used. Therefore, later, you might not be able to retrieve or remove the TextEffect you added to the collection using the original TextEffect object. The TextEffect in the collection is a copy of the original TextEffect and is considered a different TextEffect than the one you added.