FAQ's de VB6

[vbx3m]

En un módulo:

Código:

Declare Function CallWindowProc Lib "user32" Alias "CallWindowProcA" (ByVal lpPrevWndFunc As Long, ByVal hwnd As Long, ByVal MSG As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
Declare Function SetWindowLong Lib "user32" Alias "SetWindowLongA" (ByVal hwnd As Long, ByVal nIndex As Long, ByVal dwNewLong As Long) As Long
Declare Function GetMessage Lib "user32" Alias "GetMessageA" (lpMsg As MSG, ByVal hwnd As Long, ByVal wMsgFilterMin As Long, ByVal wMsgFilterMax As Long) As Long

Type POINTAPI
        x As Long
        y As Long
End Type

Type MSG
    hwnd As Long
    message As Long
    wParam As Long
    lParam As Long
    time As Long
    pt As POINTAPI
End Type

Public Const GWL_WNDPROC = -4
Public Const WM_QUERYENDSESSION = &H11
Global Const WM_CANCELMODE = &H1F

Public SDAttempted As Long
Global lpPrevWndProc As Long
Global gHW As Long

Public Sub Hook()
    lpPrevWndProc = SetWindowLong(gHW, GWL_WNDPROC, AddressOf WindowProc)
End Sub

Public Sub Unhook()
    Dim temp As Long
    temp = SetWindowLong(gHW, GWL_WNDPROC, lpPrevWndProc)
End Sub
Function WindowProc(ByVal hw As Long, ByVal uMsg As _
Long, ByVal wParam As Long, ByVal lParam As Long) As _
Long
Dim a As Long
    If uMsg = WM_QUERYENDSESSION Then
            SDAttempted = SDAttempted + 1
            WindowProc = CallWindowProc(lpPrevWndProc, hw, _
            WM_CANCELMODE, wParam, wParam)
             Exit Function
    End If
    WindowProc = CallWindowProc(lpPrevWndProc, hw, _
    uMsg, wParam, lParam)
End Function

en el form Load o Activate:

Código:

SDAttempted = 0
gHW = Me.hwnd
Hook

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