July 28, 2014
Occurs when a UI element initially gets text in a device-independent manner.
Assembly: System.Windows (in System.Windows.dll)
XMLNS for XAML: Not mapped to an xmlns.
Use a handler based on TextCompositionEventHandler to handle this event.
This event is a bubbling event. This means that if multiple handlers are registered for a sequence of objects connected by parent-child relationships in the object tree, the event is received by each object in that relationship, with the route going in the parent direction. The sender available to the event handler identifies the object where the event is handled, not necessarily the object that actually received the input condition that initiated the event. To get the object that initiated the event, use the OriginalSource value of the event's RoutedEventArgs event data. For more information on routed event concepts, see Events for Windows Phone 8.
This event occurs at the start of text input processing both at the start of IME text entry as well as regular text input. The scenario for using this event as opposed to TextInput is mainly for processing IME input. Generally, IME is only enabled for text input controls. However, the event could still bubble up to a container and be handled there.