UnhookWindowsHookEx

[eng70640]

Is there a way to check whether the API UnhookWindowsHookEx() is true ?

[Clearcode]

It returns the previous hook id (positive number) or zero on success. It sets Err.LastDLLError on failure.
To decode the failure reason:

'\\ -- [ LastSystemError ]------------------------------------------------------------------
'\\ Returns the message from the system which describes the last dll error to occur, as
'\\ held in Err.LastDllError. This function should be called as soon after the API call
'\\ which might have errored, as this member can be reset to zero by subsequent API calls.
'\\ ----------------------------------------------------------------------------------------
'\\ You have a royalty free right to use, reproduce, modify, publish and mess with this code
'\\ I'd like you to visit http://www.merrioncomputing.com for updates, but won't force you
'\\ ----------------------------------------------------------------------------------------
public Function LastSystemError() as string

Const FORMAT_MESSAGE_FROM_SYSTEM = &H1000
Dim sError as string * 500 '\\ Preinitilise a string buffer to put any error message into
Dim lErrNum as Long
Dim lErrMsg as Long

lErrNum = Err.LastDllError

lErrMsg = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM, byval 0&, lErrNum, 0, sError, len(sError), 0)

LastSystemError = Trim(sError)

End Function




and an example of how this is used...

public Sub StopHook(byval HookType as enHookTypes)

Dim lret as Long

'\\ If a hook of this type is already set, unhook this first
If HookIdByType(HookType) > 0 then
lret = UnhookWindowsHookEx(HookIdByType(HookType))
If Err.LastDllError > 0 then
Call ReportError(Err.LastDllError, "EnumHandler:StopHook", APIDispenser.LastSystemError)
End If
End If

End Sub




HTH,
Duncan

-------------------------------------------------
Ex. Datis: Duncan Jones
Merrion Computing Ltd
http://www.merrioncomputing.com

[eng70640]

Sorry if i did not make myself clear. Actually , i just want to detect see if this UnhookWindowsHookEx API has occurred . Do you have any suggestions on this ?