Unbalanced Stack?

[Chris]

I use the following keyboard hook to stop some windows functions. VS2005

This line is giving me the following error. Anyone know why or how to
fix it. As far as I can tell my functions are declared correctly.

Return CallNextHookEx( KeyboardHandle, Code, wParam, lParam)

PInvokeStackImb alance was detected
Message: A call to PInvoke function
'Utility!Utilit y.LowLevelKBHoo k::CallNextHook Ex' has unbalanced the
stack. This is likely because the managed PInvoke signature does not
match the unmanaged target signature. Check that the calling convention
and parameters of the PInvoke signature match the target unmanaged
signature.
This is the class that i am using to do this. To duplicate the error
just create a new form, create a new LowLevelKBHook object and then
press a key. You'll get the error. Thanks.

Chris

Imports System.Runtime. InteropServices
Imports System.Reflecti on
Imports System.Drawing
Imports System.Threadin g

Public Class LowLevelKBHook
Public Declare Function UnhookWindowsHo okEx Lib "user32" _
(ByVal hHook As Integer) As Integer

Public Declare Function SetWindowsHookE x Lib "user32" _
Alias "SetWindowsHook ExA" (ByVal idHook As Integer, _
ByVal lpfn As KeyboardHookDel egate, ByVal hmod As Integer, _
ByVal dwThreadId As Integer) As Integer

Private Declare Function GetAsyncKeyStat e Lib "user32" _
(ByVal vKey As Integer) As Integer

Private Declare Function CallNextHookEx Lib "user32" _
(ByVal hHook As Integer, _
ByVal nCode As Integer, _
ByVal wParam As Integer, _
ByVal lParam As KBDLLHOOKSTRUCT ) As Integer

Public Structure KBDLLHOOKSTRUCT
Public vkCode As Integer
Public scanCode As Integer
Public flags As Integer
Public time As Integer
Public dwExtraInfo As Integer
End Structure

' Low-Level Keyboard Constants
Private Const HC_ACTION As Integer = 0
Private Const LLKHF_EXTENDED As Integer = &H1
Private Const LLKHF_INJECTED As Integer = &H10
Private Const LLKHF_ALTDOWN As Integer = &H20
Private Const LLKHF_UP As Integer = &H80

' Virtual Keys
Public Const VK_TAB As Integer = &H9
Public Const VK_CONTROL As Integer = &H11
Public Const VK_ESCAPE As Integer = &H1B
Public Const VK_DELETE As Integer = &H2E

Private Const WH_KEYBOARD_LL As Integer = 13&
Public KeyboardHandle As Integer
' Implement this function to block as many
' key combinations as you'd like
Sub New()
Me.HookKeyboard ()
End Sub

Public Function IsHooked( _
ByRef Hookstruct As KBDLLHOOKSTRUCT ) As Boolean

Debug.WriteLine ("Hookstruct.vk Code: " & Hookstruct.vkCo de)
Debug.WriteLine (Hookstruct.vkC ode = VK_ESCAPE)
Debug.WriteLine (Hookstruct.vkC ode = VK_TAB)

If (Hookstruct.vkC ode = VK_ESCAPE) And _
CBool(GetAsyncK eyState(VK_CONT ROL) _
And &H8000) Then

Call HookedState("Ct rl + Esc blocked")
Return True
End If

If (Hookstruct.vkC ode = VK_TAB) And _
CBool(Hookstruc t.flags And _
LLKHF_ALTDOWN) Then

Call HookedState("Al t + Tab blockd")
Return True
End If

If (Hookstruct.vkC ode = VK_ESCAPE) And _
CBool(Hookstruc t.flags And _
LLKHF_ALTDOWN) Then

Call HookedState("Al t + Escape blocked")
Return True
End If

Return False
End Function

Private Sub HookedState(ByV al Text As String)
Debug.WriteLine (Text)
End Sub

Public Function KeyboardCallbac k(ByVal Code As Integer, _
ByVal wParam As Integer, _
ByRef lParam As KBDLLHOOKSTRUCT ) As Integer

If (Code = HC_ACTION) Then
Debug.WriteLine ("Calling IsHooked")

If (IsHooked(lPara m)) Then
Return 1
End If

End If

Return CallNextHookEx( KeyboardHandle, _
Code, wParam, lParam)

End Function
Public Delegate Function KeyboardHookDel egate( _
ByVal Code As Integer, _
ByVal wParam As Integer, ByRef lParam As KBDLLHOOKSTRUCT ) _
As Integer

<MarshalAs(Unma nagedType.Funct ionPtr)> _
Private callback As KeyboardHookDel egate

Public Sub HookKeyboard()
callback = New KeyboardHookDel egate(AddressOf KeyboardCallbac k)

KeyboardHandle = SetWindowsHookE x( _
WH_KEYBOARD_LL, callback, _
Marshal.GetHINS TANCE( _
[Assembly].GetExecutingAs sembly.GetModul es()(0)).ToInt3 2, 0)

Call CheckHooked()
End Sub

Public Sub CheckHooked()
If (Hooked()) Then
Debug.WriteLine ("Keyboard hooked")
Else
Debug.WriteLine ("Keyboard hook failed: " & Err.LastDllErro r)
End If
End Sub

Private Function Hooked() As Boolean
Hooked = KeyboardHandle <> 0
End Function

Public Sub UnhookKeyboard( )
If (Hooked()) Then
Call UnhookWindowsHo okEx(KeyboardHa ndle)
End If
End Sub

End Class

[Herfried K. Wagner [MVP]]

"Chris" <[e-mail]> schrieb im Newsbeitrag:

I use the following keyboard hook to stop some windows functions. VS2005

This line is giving me the following error. Anyone know why or how to
fix it. As far as I can tell my functions are declared correctly.

Return CallNextHookEx( KeyboardHandle, Code, wParam, lParam)

PInvokeStackImb alance was detected
Message: A call to PInvoke function
'Utility!Utilit y.LowLevelKBHoo k::CallNextHook Ex' has unbalanced the
stack. This is likely because the managed PInvoke signature does not
match the unmanaged target signature. Check that the calling convention
and parameters of the PInvoke signature match the target unmanaged
signature.
[...]
Private Declare Function CallNextHookEx Lib "user32" _
(ByVal hHook As Integer, _
ByVal nCode As Integer, _
ByVal wParam As Integer, _
ByVal lParam As KBDLLHOOKSTRUCT ) As Integer

=> 'ByRef lParam As KBDLLHOOKSTRUCT '.

--
M S Herfried K. Wagner
M V P <URL:http://dotnet.mvps.org/>
V B <URL:http://classicvb.org/petition/>

[Chris]

Herfried K. Wagner [MVP] wrote:

"Chris" <[e-mail]> schrieb im Newsbeitrag:

I use the following keyboard hook to stop some windows functions. VS2005

This line is giving me the following error. Anyone know why or how to
fix it. As far as I can tell my functions are declared correctly.

Return CallNextHookEx( KeyboardHandle, Code, wParam, lParam)

PInvokeStackImb alance was detected
Message: A call to PInvoke function
'Utility!Utilit y.LowLevelKBHoo k::CallNextHook Ex' has unbalanced the
stack. This is likely because the managed PInvoke signature does not
match the unmanaged target signature. Check that the calling
convention and parameters of the PInvoke signature match the target
unmanaged signature.
[...]
Private Declare Function CallNextHookEx Lib "user32" _
(ByVal hHook As Integer, _
ByVal nCode As Integer, _
ByVal wParam As Integer, _
ByVal lParam As KBDLLHOOKSTRUCT ) As Integer

=> 'ByRef lParam As KBDLLHOOKSTRUCT '.

Thanks...