Imports System.Runtime.InteropServices
Imports System.Reflection
Public Class Form1
Private Sub Form1_HandleCreated(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.HandleCreated
KeyboardJammer.Jam()
End Sub
Private Sub Form1_HandleDestroyed(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.HandleDestroyed
KeyboardJammer.UnJam()
End Sub


End Class
Public Class KeyboardJammer
Private Delegate Function HookCallback(ByVal nCode As Integer, ByVal wParam As Integer, ByVal lParam As IntPtr) As Integer
Private Shared HookDelegate As HookCallback
Private Shared HookId As Integer
Private Const Wh_Keyboard_LL As Integer = 13
Private Const Vk_Tab As Integer = 9
Private Const Vk_Escape As Integer = 27
Private Const vk_Del As Integer = 46
Private Const Vk_F4 As Integer = 115
Private Const VK_LWinKey As Integer = 91
Private Const VK_RWinKey As Integer = 92
Private Shared Function KeyBoardHookProc(ByVal nCode As Integer, ByVal wParam As Integer, ByVal lParam As IntPtr) As Integer
'All keyboard events will be sent here.
'Don't process just pass along.
If nCode < 0 Then
Return CallNextHookEx(HookId, nCode, wParam, lParam)
End If
'Extract the keyboard structure from the lparam
'This will contain the virtual key and any flags.
'This is using the my.computer.keyboard to get the
'flags instead
Dim KeyboardSruct As KBDLLHOOKSTRUCT = Marshal.PtrToStructure(lParam, GetType(KBDLLHOOKSTRUCT))
MsgBox(KeyboardSruct.vkCode.ToString, MsgBoxStyle.OkOnly)
If KeyboardSruct.vkCode = Vk_Tab And My.Computer.Keyboard.AltKeyDown Then
'Alt Tab
Return 1
ElseIf KeyboardSruct.vkCode = Vk_Escape And My.Computer.Keyboard.CtrlKeyDown Then
'Control Escape
Return 1
ElseIf KeyboardSruct.vkCode = VK_LWinKey Or KeyboardSruct.vkCode = VK_RWinKey Then
'Left Windows Key or Rigth Windows Key
Return 1
ElseIf KeyboardSruct.vkCode = vk_Del And My.Computer.Keyboard.CtrlKeyDown And My.Computer.Keyboard.AltKeyDown Then
'Ctrl Alt Del
Return 1
ElseIf KeyboardSruct.vkCode = Vk_F4 And My.Computer.Keyboard.AltKeyDown Then
'Alt F4
Return 1
End If
'Send the message along
Return CallNextHookEx(HookId, nCode, wParam, lParam)
End Function
Public Shared Sub Jam()
'Add the low level keyboard hook
If HookId = 0 Then
HookDelegate = AddressOf KeyBoardHookProc
HookId = SetWindowsHookEx(Wh_Keyboard_LL, HookDelegate, Marshal.GetHINSTANCE(Assembly.GetExecutingAssembly.GetModules()(0)), 0)
If HookId = 0 Then
'error
End If
End If
End Sub
Public Shared Sub UnJam()
'Remove the hook
UnhookWindowsHookEx(HookId)
End Sub
<DllImport("user32.dll", CharSet:=CharSet.Auto, CallingConvention:=CallingConvention.StdCall)> _
Private Shared Function CallNextHookEx( _
ByVal idHook As Integer, _
ByVal nCode As Integer, _
ByVal wParam As IntPtr, _
ByVal lParam As IntPtr) As Integer
End Function
<DllImport("user32.dll", CharSet:=CharSet.Auto, CallingConvention:=CallingConvention.StdCall, SetLastError:=True)> _
Private Shared Function SetWindowsHookEx( _
ByVal idHook As Integer, _
ByVal HookProc As HookCallback, _
ByVal hInstance As IntPtr, _
ByVal wParam As Integer) As Integer
End Function
<DllImport("user32.dll", CharSet:=CharSet.Auto, CallingConvention:=CallingConvention.StdCall, SetLastError:=True)> _
Private Shared Function UnhookWindowsHookEx(ByVal idHook As Integer) As Integer
End Function
Private Structure KBDLLHOOKSTRUCT
Public vkCode As Integer
Public scanCode As Integer
Public flags As Integer
Public time As Integer
Public dwExtraInfo As IntPtr
End Structure
End Class