int GetSel( int nIndex ) const;
nIndex
Specifies the zero-based index of the item.
Retrieves the selection state of an item. This member function works with both single and multiple-selection list boxes.
A positive number if the specified item is selected; otherwise, it is 0. The return value is LB_ERR if an error occurs.
LB_GETSEL, CListBox::SetSel