def METHOD_NAME(self, evt):
    if evt.GetWheelRotation() > 0 and evt.GetWheelAxis() == wx.MOUSE_WHEEL_VERTICAL:
        self.SetValue(self.ctrl.Value + self.ctrl.Increment)
    elif evt.GetWheelRotation() < 0 and evt.GetWheelAxis() == wx.MOUSE_WHEEL_VERTICAL:
        self.SetValue(self.ctrl.Value - self.ctrl.Increment)
    else:
        evt.Skip()