virtual protected void OnMonitorScroll(MonitorScrollEventArgs e)
 {
     if (MonitorScroll != null)
     {
         MonitorScroll(this, e);
     }
 }
 protected virtual void OnMonitorScroll(MonitorScrollEventArgs e)
 {
     if (MonitorScroll != null)
     {
         MonitorScroll(this, e);
     }
 }