An application sends an EM_GETSEL message to get the starting and ending character positions of the current selection in an edit control.
EM_GETSEL
wParam = (WPARAM) (LPDWORD) lpdwStart; // receives starting position
lParam = (LPARAM) (LPDWORD) lpdwEnd; // receives ending position
The return value is a zero-based 32-bit value with the starting position of the selection in the low-order word and the position of the first character after the last selected character in the high-order word. If either of these values exceeds 65, 535, the return value is -1.
In a rich edit control, if the selection is not entirely contained in the first 64K, use the message EM_EXGETSEL.
Windows NT: Requires version 3.1 or later.
Windows: Requires Windows 95 or later.
Windows CE: Requires version 1.0 or later.
Header: Declared in winuser.h.
Edit Controls Overview, Edit Control Messages, EM_EXGETSEL, EM_SETSEL