通过Hook技术屏蔽系统键

add a checkbox named chkDisable.caption="&Disable ALT-TAB, ALT-ESC, CTRL-ESC,LWin,RWin,Win+Any"
to a new from named frmMain.frm in new project hook_kb_LL.vbp
add code below:

---

Option Explicit

Dim hhkLowLevelKybd As Long

Private Sub chkDisable_Click()
If chkDisable = vbChecked Then
    hhkLowLevelKybd = SetWindowsHookEx(WH_KEYBOARD_LL, AddressOf  LowLevelKeyboardProc, App.hInstance, 0)
Else
    UnhookWindowsHookEx hhkLowLevelKybd
    hhkLowLevelKybd = 0
End If
End Sub

Private Sub Form_Unload(Cancel As Integer)
If hhkLowLevelKybd <> 0 Then UnhookWindowsHookEx hhkLowLevelKybd
End Sub

---

in new module named modDisableLowLevelKeys.bas
code below:

---

Option Explicit

Public Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" (Destination As Any, Source As Any, ByVal Length As Long)
Public Declare Function GetKeyState Lib "user32" (ByVal nVirtKey As Long) As Integer
Public Declare Function SetWindowsHookEx Lib "user32" Alias "SetWindowsHookExA" (ByVal idHook As Long, ByVal lpfn As Long, ByVal hmod As Long, ByVal dwThreadId As Long) As Long
Public Declare Function CallNextHookEx Lib "user32" (ByVal hHook As Long, ByVal nCode As Long, ByVal wParam As Long, lParam As Any) As Long
Public Declare Function UnhookWindowsHookEx Lib "user32" (ByVal hHook As Long) As Long
Public Const HC_ACTION = 0
Public Const WM_KEYDOWN = &H100
Public Const WM_KEYUP = &H101
Public Const WM_SYSKEYDOWN = &H104
Public Const WM_SYSKEYUP = &H105
Public Const VK_TAB = &H9
Public Const VK_CONTROL = &H11
Public Const VK_ESCAPE = &H1B

Public Const WH_KEYBOARD_LL = 13
Public Const LLKHF_ALTDOWN = &H20

Public Type KBDLLHOOKSTRUCT
    vkCode As Long
    scanCode As Long
    flags As Long
    time As Long
    dwExtraInfo As Long
End Type

Dim p As KBDLLHOOKSTRUCT

Public Function LowLevelKeyboardProc(ByVal nCode As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
   Dim fEatKeystroke As Boolean
  
   If (nCode = HC_ACTION) Then
      If wParam = WM_KEYDOWN Or wParam = WM_SYSKEYDOWN Or wParam = WM_KEYUP Or wParam = WM_SYSKEYUP Then
         CopyMemory p, ByVal lParam, Len(p)
         fEatKeystroke = _
            ((p.vkCode = VK_TAB) And ((p.flags And LLKHF_ALTDOWN) <> 0)) Or _
            ((p.vkCode = VK_ESCAPE) And ((p.flags And LLKHF_ALTDOWN) <> 0)) Or _
            ((p.vkCode = VK_ESCAPE) And ((GetKeyState(VK_CONTROL) And &H8000) <> 0)) Or _
            ((p.vkCode = 91) Or (p.vkCode = 92) Or (p.vkCode = 93)) '左右Win 和徽标键
            End If
    End If
   
    If fEatKeystroke Then
        LowLevelKeyboardProc = -1
    Else
        LowLevelKeyboardProc = CallNextHookEx(0, nCode, wParam, ByVal lParam)
    End If
End Function