This macro returns the length of the text of the indexed item in the List Box.

#define INCL_WINWINDOWMGR /* Or use INCL_WIN, INCL_PM, */
#include <os2.h>

HWND     hwndLbox;  /*  Listbox handle. */
SHORT    index;     /*  Index of the item in the List Box. */
SHORT    sRetLen;   /*  Text length of the indexed item. */

sRetLen = WinQueryLboxItemTextLength(hwndLbox,
            index);