MouseWheel example for Visual Basic

Private Sub LEADRasterView_MouseWheel(ByVal nDelta As Integer, ByVal Shift As Integer, ByVal x As Long, ByVal y As Long)
   If (Shift = 2) Then
       If (nDelta < 0) Then
          If (LEADRasterView.PaintZoomFactor< 100 * 16) Then
             LEADRasterView.PaintZoomFactor = LEADRasterView.PaintZoomFactor * 2
          End If
       Else
          If (LEADRasterView.PaintZoomFactor > 100 / 16) Then
             LEADRasterView.PaintZoomFactor = LEADRasterView.PaintZoomFactor / 2
          End If
       End If
    Else
       If (Shift = 3) Then
          LEADRasterView.HScrollInfo.Pos = LEADRasterView.HScrollInfo.Pos - nDelta
       Else
          LEADRasterView.VScrollInfo.Pos = LEADRasterView.VScrollInfo.Pos - nDelta
       End If
    End If
End Sub