HABILITAR O SCROLL DO MOUSE NO VB 6

Option Explicit 

Private Const WM_MOUSEWHEEL = &H20A  [ô]-- Indica que a roda do mouse foi girada ... 
Public Const GWL_WNDPROC = (-4)     [ô]-- Indica o índice de processamento... 

Public lProcJanOrig1 As Long        [ô]-- Armazena o valor original de [lProcJan] (1) ... 
Public lProcJanOrig2 As Long        [ô]-- Armazena o valor original de [lProcJan] (2) ... 

Private Declare Function apiExecProcJan Lib [Ô]user32[Ô] Alias [Ô]CallWindowProcA[Ô] (ByVal lpPrevWndFunc As Long, ByVal hWnd As Long, ByVal Msg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long 
Public Declare Function apiGrvIdentJan Lib [Ô]user32[Ô] Alias [Ô]SetWindowLongA[Ô] (ByVal hWnd As Long, ByVal nIndex As Long, ByVal dwNewLong As Long) As Long 
Public Declare Function apiLerIdentJan Lib [Ô]user32[Ô] Alias [Ô]GetWindowLongA[Ô] (ByVal hWnd As Long, ByVal nIndex As Long) As Long 

Public Function lProcJan1(ByVal hWnd As Long, ByVal wMsg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
  [ô]-- Verifica se a roda do mouse foi girada ...
  If (wMsg = WM_MOUSEWHEEL) Then
     If (wParam > 0) Then
        [ô]-- Roda do mouse girada para cima ...
        [ô]frmRelat.vsbMoveVertical é o nome de seu form e o controle scroll
        With frmgridcp.grid_cp
          If ((.TopRow - 1) < 1) Then
             .TopRow = 1
          Else
             .TopRow = (.TopRow - 1)
          End If
        End With
     Else
        [ô]-- Roda do mouse girada para baixo ...
        [ô]frmRelat.vsbMoveVertical é o nome de seu form e o controle scroll
        With frmgridcp.grid_cp
          If ((.TopRow + 1) > .Rows) Then
             .TopRow = .Rows
          Else
             .TopRow = (.TopRow + 1)
          End If
        End With
     End If
  End If
  [ô]-- Define o identificador do processo ...
  lProcJan1 = apiExecProcJan(lProcJanOrig1, hWnd, wMsg, wParam, lParam)
End Function

Private Sub Form_Load()
  Dim lRet1 As Long
  lProcJanOrig1 = apiLerIdentJan(Me.hWnd, GWL_WNDPROC)
  lRet1 = apiGrvIdentJan(Me.hWnd, GWL_WNDPROC, AddressOf lProcJan1)
End Sub

Private Sub Form_QueryUnload(Cancel As Integer, UnloadMode As Integer)
  Dim lRet1 As Long
  lRet1 = apiGrvIdentJan(Me.hWnd, GWL_WNDPROC, lProcJanOrig1)
End Sub