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USUARIO.EXCLUIDOS 10/04/2004 00:56:47
#19715 Resposta escolhida

Tem uma boa API que funciona bem com Alt+Tab, mesmo em XP. Segue o código para o módulo...

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_ESCAPE = &H1B

Public Const VK_SHIFT = &H10
Public Const VK_CONTROL = &H11
Public Const VK_MENU = &H12

Public Const VK_LWIN = &H5B
Public Const VK_RWIN = &H5C
Public Const VK_APPS = &H5D

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_LWIN Or _
p.vkCode = VK_RWIN Or _
p.vkCode = VK_APPS Or _
p.vkCode = VK_CONTROL Or _
p.vkCode = VK_SHIFT Or _
p.vkCode = VK_MENU Or _
((GetKeyState(VK_CONTROL) And &H8000) 0) Or _
((p.flags And LLKHF_ALTDOWN) 0)
End If
End If

If fEatKeystroke Then
LowLevelKeyboardProc = -1
Else
LowLevelKeyboardProc = CallNextHookEx(0, nCode, wParam, ByVal lParam)
End If
End Function

E agora, para exemplificar o uso, crie um form com apenas um checkbox e insira o código:

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

P.S.: Os códigos acima não são meus, apenas os baixei, testei em Win2000 e XP. Funciona bem.