FAQ's de VB6

[vbx3m]

Modulo:

Código:

Public hHook As Long
Public Const WH_CALLWNDPROCRET = 12
Public Const GWL_HINSTANCE = (-6)
Private Type tagCWPRETSTRUCT
    lResult As Long
    lParam As Long
    wParam As Long
    message As Long
    hWnd As Long
End Type
Private Const WM_INITDIALOG = &H110
Public Declare Function GetWindowLong Lib "user32" Alias "GetWindowLongA" _
    (ByVal hWnd As Long, ByVal nIndex As Long) As Long
Public Declare Function GetCurrentThreadId Lib "kernel32" () As Long
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
Private Declare Function UnhookWindowsHookEx Lib "user32" _
    (ByVal hHook As Long) As Long
Private Declare Function CallNextHookEx Lib "user32" _
    (ByVal hHook As Long, ByVal nCode As Long, _
    ByVal wParam As Long, lParam As Any) As Long
Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" _
    (Destination As Any, Source As Any, ByVal Length As Long)
Private Const IDOK = 1
Private Const IDCANCEL = 2
Private Const IDABORT = 3
Private Const IDRETRY = 4
Private Const IDIGNORE = 5
Private Const IDYES = 6
Private Const IDNO = 7
Private Declare Function SetDlgItemText Lib "user32" Alias "SetDlgItemTextA" _
    (ByVal hDlg As Long, ByVal nIDDlgItem As Long, _
    ByVal lpString As String) As Long
Public Function CallWndRetProc(ByVal nCode As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
    Dim lr As Long
    Dim s As tagCWPRETSTRUCT
    lr = CallNextHookEx(hHook, nCode, wParam, lParam)
    If (nCode < 0) Then
        CallWndRetProc = lr
        Exit Function
    End If
    Call CopyMemory(s, ByVal lParam, Len(s))
    If (s.message = WM_INITDIALOG) Then
        Call SetDlgItemText(s.hWnd, IDYES, "Aprobar")
        Call SetDlgItemText(s.hWnd, IDNO, "Rechazar")
        UnhookWindowsHookEx hHook
        lr = 0&
    End If
    CallWndRetProc = lr
End Function

Form:

Código:

   Dim hInst As Long
    Dim Thread As Long
    Dim i As Long
    hInst = GetWindowLong(Me.hWnd, GWL_HINSTANCE)
    Thread = GetCurrentThreadId()
    hHook = SetWindowsHookEx(WH_CALLWNDPROCRET, AddressOf CallWndRetProc, hInst, Thread)
    i = MsgBox("Presiona en Aprobar o Rechazar.", vbYesNo)
    If i = vbYes Then
        Label1 = "Has presionado en Aprobar"
    ElseIf i = vbNo Then
        Label1 = "Has presionado en Rechazar"
    End If