Hi,
you can try this code.
CheckBoxList1.SelectedItem
But checkboxlist is you can select multiple options in that case it returns only
lower item that means
top selected item in your selected items.
If you want to get all selected items then
foreach (ListItem boxItem in CheckBoxList1.Items)
{
if (boxItem.Selected == true)
{
categoryID.Add((string)boxItem.Value);
}
}
All the Best