Occurs when the InputManager starts to process the input item.
Assembly: PresentationCore (in PresentationCore.dll)
A filter is any code that listens to or PostProcessInput. Filters can modify the input staging area.
The handlers attached to are invoked in reverse order so that handlers added by the users are invoked before handlers in the system.
Input is processed in WPF in the follow stages:
Pre-process stage. The input manager raises the event.
Pre-notify stage. The input manager raises the PreNotifyInput event.
The WPF input event or events are raised.
Post-notify stage. The input manager raises the PostNotifyInput event.
Post-process stage. The input manager raises the PostProcessInput event.