[RESOLVED] Keyboard Hooking Question

Ok, here I go again... I built an application that runs on top of a game that I play. I use a keyboard hook to intercept certain keys and pass them through my app. The problem I am haveing is that the commands are getting passed through my application, but is there a way to stop the keys from then being sent to the game as well.

For example I want to intercept Ctrl + T which in my application does something, but in the game, it opens a window. What I want to happen is it to fire the event in my app and then not send that combination to the game and open the window.

I hope I was clear with my question and I thank you in advance for any help

This is the function I am currently using, which works, but the keys still get sent to the game

VB Code:

Public Function IsHooked(ByRef Hookstruct As KBDLLHOOKSTRUCT) As Boolean
 
        '  CTL Keys
 
        Dim key As Integer
        Dim mcr As Integer
        Dim VK_KEY As Integer
 
        For i As Integer = 0 To setKeys.GetUpperBound(0)
            key = setKeys(i).subKey 'The subkey (1=Ctrl,2=Alt,0=none)
            mcr = setKeys(i).mcr 'The macro index to be fired
            VK_KEY = setKeys(i).key 'The key value
 
            If key = 1 Then 'Subkey is Control
                If (Hookstruct.vkCode = VK_KEY) And CBool(GetAsyncKeyState(VK_CONTROL) And &H8000) _
                        And CBool(Hookstruct.flags And LLKHF_UP) Then
                    Call mcrFire(mcr)
                    Return True
                ElseIf (Hookstruct.vkCode = VK_KEY) And CBool(GetAsyncKeyState(VK_CONTROL) And &H8000) Then
                    'Do nothing
                End If
            ElseIf key = 2 Then 'Subkey is Alt
                If (Hookstruct.vkCode = VK_KEY) And CBool(Hookstruct.flags And LLKHF_ALTDOWN) _
                    And CBool(Hookstruct.flags And LLKHF_UP) Then
                    Call mcrFire(mcr)
                    Return True
                ElseIf (Hookstruct.vkCode = VK_KEY) And CBool(Hookstruct.flags And LLKHF_ALTDOWN) Then
                    'Do nothing
                End If
            Else 'No Subkey
                If (Hookstruct.vkCode = VK_KEY) And CBool(Hookstruct.flags And LLKHF_UP) Then
                    Call mcrFire(mcr)
                    Return True
                ElseIf (Hookstruct.vkCode = VK_KEY) Then
                    'Do nothing
                End If
            End If
        Next i
 
        'Page up and down for switching macro sets
 
        If (Hookstruct.vkCode = VK_NEXT) And CBool(Hookstruct.flags And LLKHF_UP) Then
            MacroSets(1)
            Return True
        ElseIf (Hookstruct.vkCode = VK_NEXT) Then
            Return True
        End If
 
        If (Hookstruct.vkCode = VK_PRIOR) And CBool(Hookstruct.flags And LLKHF_UP) Then
            MacroSets(-1)
            Return True
        ElseIf (Hookstruct.vkCode = VK_PRIOR) Then
            Return True
        End If
 
        Return False
    End Function

unfortunately, the low level keyboard hook does not allow you to change messages.

see my signature for a link to hooking external processes

Thanks for the response Moeur. I actually figured out what I was doing wrong and got it working.

I needed to return True on the key down event because it was sending to the game when the key down event was firing and then to my app on the key up event.

Here is my fixed code

VB Code:

Public Function IsHooked(ByRef Hookstruct As KBDLLHOOKSTRUCT) As Boolean
 
        '  CTL Keys
 
        Dim key As Integer
        Dim mcr As Integer
        Dim VK_KEY As Integer
 
        For i As Integer = 0 To setKeys.GetUpperBound(0)
            key = setKeys(i).subKey 'The subkey (1=Ctrl,2=Alt,0=none)
            mcr = setKeys(i).mcr 'The macro index to be fired
            VK_KEY = setKeys(i).key 'The key value
 
            If key = 1 Then 'Subkey is Control
                If (Hookstruct.vkCode = VK_KEY) And CBool(GetAsyncKeyState(VK_CONTROL) And &H8000) _
                        And CBool(Hookstruct.flags And LLKHF_UP) Then
                    Call mcrFire(mcr)
                    Return True
                ElseIf (Hookstruct.vkCode = VK_KEY) And CBool(GetAsyncKeyState(VK_CONTROL) And &H8000) Then
                    Return True '<-------Changed this to Return True
                End If
            ElseIf key = 2 Then 'Subkey is Alt
                If (Hookstruct.vkCode = VK_KEY) And CBool(Hookstruct.flags And LLKHF_ALTDOWN) _
                    And CBool(Hookstruct.flags And LLKHF_UP) Then
                    Call mcrFire(mcr)
                    Return True
                ElseIf (Hookstruct.vkCode = VK_KEY) And CBool(Hookstruct.flags And LLKHF_ALTDOWN) Then
                    Return True '<-------Changed this to Return True
                End If
            Else 'No Subkey
                If (Hookstruct.vkCode = VK_KEY) And CBool(Hookstruct.flags And LLKHF_UP) Then
                    Call mcrFire(mcr)
                    Return True
                ElseIf (Hookstruct.vkCode = VK_KEY) Then
                    Return True '<-------Changed this to Return True
                End If
            End If
        Next i
 
        'Page up and down for switching macro sets
 
        If (Hookstruct.vkCode = VK_NEXT) And CBool(Hookstruct.flags And LLKHF_UP) Then
            MacroSets(1)
            Return True
        ElseIf (Hookstruct.vkCode = VK_NEXT) Then
            Return True
        End If
 
        If (Hookstruct.vkCode = VK_PRIOR) And CBool(Hookstruct.flags And LLKHF_UP) Then
            MacroSets(-1)
            Return True
        ElseIf (Hookstruct.vkCode = VK_PRIOR) Then
            Return True
        End If
 
        Return False
    End Function

Thanks again.