public static void AddMessageFilter(ChartWinControl chartWinControl)
 {
     if (KeyFilter == null)
     {
         KeyFilter = new KeyMessageFilter(chartWinControl);
         Application.AddMessageFilter(KeyFilter);
     }
 }
 /// <summary>
 /// Add KeyEventHandler to current application
 /// </summary>
 /// <param name="keh"></param>
 static public void AddMessageFilter(KeyEventHandler keh)
 {
     if (KeyFilter == null)
     {
         KeyFilter = new KeyMessageFilter(new KeyEventHandler(keh));
         Application.AddMessageFilter(KeyFilter);
     }
 }