키보드 후킹(Hooking)을 통한 HomeKey 방지

'===================== 키보드 Hook을 통한 Window Home 키 입력 방지

    Private Const WM_KEYUP As Integer = &H101
    Private Const WM_KEYDOWN As Short = &H100S
    Private Const WM_SYSKEYDOWN As Integer = &H104
    Private Const WM_SYSKEYUP As Integer = &H105

    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

    Private Declare Function UnhookWindowsHookEx Lib "user32" (ByVal hHook As Integer) As Integer
    Private Declare Function SetWindowsHookEx Lib "user32" Alias "SetWindowsHookExA" (ByVal idHook As Integer, ByVal lpfn As KeyboardHookDelegate, ByVal hmod As Integer, ByVal dwThreadId As Integer) As Integer
    Private Declare Function GetAsyncKeyState 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
    Private Delegate Function KeyboardHookDelegate(ByVal Code As Integer, ByVal wParam As Integer, ByRef lParam As KBDLLHOOKSTRUCT) As Integer


    Private KeyboardHandle As IntPtr = 0 'hook 핸들
    Private callback As KeyboardHookDelegate = Nothing ' hook Delegate 

    Private Function Hooked()
        Return KeyboardHandle <> 0 'If KeyboardHandle = 0 it means that it isn't hooked so return false, otherwise return true
    End Function

    Public Sub HookKeyboard()
        callback = New KeyboardHookDelegate(AddressOf KeyboardCallback)
        KeyboardHandle = SetWindowsHookEx(13, callback, Process.GetCurrentProcess.MainModule.BaseAddress, 0)
        If KeyboardHandle <> 0 Then
            Debug.Write(vbCrLf & "[Keyboard Hooked]" & vbCrLf)
        End If
    End Sub

    Public Sub UnhookKeyboard()
        If (Hooked()) Then
            If UnhookWindowsHookEx(KeyboardHandle) <> 0 Then
                Debug.Write(vbCrLf & "[Keyboard Unhooked]")
                KeyboardHandle = 0 'We have unhooked successfully
            End If
        End If
    End Sub

    Public Function KeyboardCallback(ByVal Code As Integer, ByVal wParam As Integer, ByRef lParam As KBDLLHOOKSTRUCT) As Integer
        'Variable to hold the text describing the key pressed
        Dim Key = lParam.vkCode

        'If event is KEYDOWN
        If wParam = WM_KEYDOWN Or wParam = WM_SYSKEYDOWN Then
            'If we can block events
            If Code >= 0 Then
                If Key = 91 Or Key = 92 Then
                    Return 1 'Block event
                End If

            End If
        End If
        ' Debug.Write(Key)

        'Return CallNextHookEx(KeyboardHandle, Code, wParam, lParam) 'Let event go to the other applications
    End Function