Subclassing and Hooking with Visual Basic

Name

CallWindowProc

Synopsis

Used to call a function specified by the lpPrevWndFunc function pointer:

Public Declare Function CallWindowProc Lib "user32" Alias "CallWindowProcA" _
		(ByVal lpPrevWndFunc As Long, _
		ByVal hWnd As Long, _
		ByVal Msg As Long, _
		ByVal wParam As Long, _
		ByVal lParam As Long) As Long

Parameters

lPrevWndFunc

A pointer to the window procedure to be called

hWnd

The handle of a window

Msg

The message to send to the target window procedure

wParam

The first parameter of the message

lParam

The second parameter of the message

Return Value

This function’s return value depends on the type of message (identified by the Msg argument) processed.