LB_INSERTSTRING
wParam = (WPARAM) index; /* item index */
lParam = (LPARAM) (LPCSTR) lpsz; /* address of string to insert */
An application sends an LB_INSERTSTRING message to insert a string into a list box. Unlike the LB_ADDSTRING message, the LB_INSERTSTRING message does not cause a list with the LBS_SORT style to be sorted.
index
Value of wParam. Specifies the zero-based index of the position at which to insert the string. If this parameter is –1, the string is added to the end of the list.
lpsz
Value of lParam. Points to the null-terminated string that is to be inserted. If the list was created with an owner-drawn style but without the LBS_HASSTRINGS style, the value of the lpsz parameter is stored rather than the string it would otherwise point to.
The return value is the index of the position at which the string was inserted. The return value is LB_ERR if an error occurs. The return value is LB_ERRSPACE if insufficient space is available to store the new string.
This example inserts the string “my string” into the third position of the list box:
SendDlgItemMessage
(hdlg, ID_MYLISTBOX, LB_INSERTSTRING, 2, (LPARAM) ((LPCSTR) "my string"));