void ThisAddIn_SheetChange(object Sh, Microsoft.Office.Interop.Excel.Range Target)
        {
            //MessageBox.Show("ThisAddIn_SheetChange");
            MyRibbon.InvalidateRibbon();

            PivotHelper.PostSheetChange(Target);
        }
 void ThisAddIn_SheetActivate(object Sh)
 {
     //MessageBox.Show("ThisAddIn_SheetActivate");
     MyRibbon.InvalidateRibbon();
 }
 void ThisAddIn_SelectionChange(object Sh, Microsoft.Office.Interop.Excel.Range Target)
 {
     //MessageBox.Show("ThisAddIn_SelectionChange");
     MyRibbon.InvalidateRibbon();
 }