Okay hello everyone, so I'm using this class to protect app from user using hotkeys while form is running:
Imports System.Runtime.InteropServices
Imports System.Reflection
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 Function KeyBoardHookProc(ByVal nCode As Integer, ByVal wParam As Integer, ByVal lParam As IntPtr) As Integer
If nCode < 0 Then
Return CallNextHookEx(HookId, nCode, wParam, lParam)
End If
Dim KeyboardSruct As KBDLLHOOKSTRUCT = Marshal.PtrToStructure(lParam, GetType(KBDLLHOOKSTRUCT))
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 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 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
Now I call it on form open and form close:
Private Sub Form1_FormClosing(sender As Object, e As FormClosingEventArgs) Handles Me.FormClosing
KeyboardJammer.UnJam()
End Sub
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
KeyboardJammer.Jam()
End Sub
I have 1 button that shows settings form and closing this form with code:
settings.Show()
Me.Close()
And in "settings" form i have button that opens back Form1:
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim newform As New Form1()
newform.Show()
Close()
End Sub
Now problem is, when i run my .exe form1 loads up and you cant use hotkeys like ctrl+esc, alt+f4 etc..
But when I close form1 and open settings, I can use hotkeys which is okay, but when i hit again that Button1 on "Settings" form and my Form1 shows again I can still use HOTKEYS which is NOT GOOD... Any ides whats wrong?
