count selected items of checkboxlist and also separate it with comma

A simple way to count only selected items of checkboxlist

 var totalcount = CheckBoxList1.Items.Cast<ListItem>().Where(item => item.Selected).Count();


now If you want separte it with comma then



 foreach (ListItem selectedItem in CheckBoxList1.Items)
        {
            if (selectedItem.Selected)
            {


                if (string.IsNullOrEmpty(selectedExch))


                    selectedExch = selectedItem.Value;


                else


                    selectedExch = selectedExch + "," + selectedItem.Value;


            }


        }