Send an LB_GETCURSEL message to retrieve the index of the currently selected item, if any, in a single-selection list box.
LB_GETCURSEL wParam = 0; // not used; must be zero lParam = 0; // not used; must be zero
This message has no parameters.
In a single-selection list box, the return value is the zero-based index of the currently selected item. If there is no selection, the return value is LB_ERR.
Do not send this message to a multiple-selection list box.
To retrieve the indexes of the selected items in a multiple-selection list box, use the LB_GETSELITEMS message. To determine whether the item that has the focus rectangle in a multiple selection list box is selected, use the LB_GETSEL message.
If sent to a multiple-selection list box, LB_GETCURSEL returns the index of the item that has the focus rectangle. If no items are selected, it returns zero.