Invoked whenever an unhandled DragDrop.QueryContinueDrag attached routed event reaches an element derived from this class in its route. Implement this method to add class handling for this event.
Assembly: PresentationFramework (in PresentationFramework.dll)
This method has no default implementation. Calling base() in your implementation is still recommended, in case an intermediate class in the inheritance implemented this method. You may call base() either before or after your special handling, depending on your requirements.
The purpose of this method is somewhat similar to common language runtime (CLR) event pattern On* methods: it lets you handle the matching event from derived classes by using a class handler instead of an instance handler. In this case, the matching event is a routed event. The implementation pattern of the On* methods is different for routed events because the routed event may have been raised by a child element, which is not necessarily the element that invokes handlers. Therefore, your implementation needs to take the event arguments' source properties into account (and should not try to re-raise the event in most cases). Subclasses of TextBoxBase can choose to call private class handler methods when the event is received along the route. One scenario is to take the arguments of the event and mark the event as handled.