HwndSource.AddHook Method (HwndSourceHook)
Adds an event handler that receives all window messages.
Assembly: PresentationCore (in PresentationCore.dll)
This method is not available in the Internet security zone.
Most Win32 messages that reach the HwndSource have an approximate WPF equivalent. You use to handle the cases where the message has no WPF equivalent.
The HwndSourceHook delegate resembles the parameter profile of a Win32 main window procedure. All window messages that the main window procedure of the HwndSource parent window receives are also forwarded to the HwndSourceHook delegates.
Hooks are called in the order that they were added. If any hook returns handled=true for a message, the hooks after it in the call order are not called for that message.
Available since 3.0