Retrieves the information of a specified selection when multiple selections are available. You can send this message explicitly or use the Editor_GetMultiSel inline function.
wParam = (WPARAM) (UINT_PTR) iSel;
lParam = (LPARAM) (SEL_INFO*) pSelInfo;
Index of the selection of which the information will be retrieved. If -1 is specified, the number of selections will be returned.
Pointer to the SEL_INFO structure.
If iSel is -1, the return value is the number of selection. Otherwise, TRUE if the specified selection information is retrieved. The return value is FALSE if the selection is not multiple selection mode or an error occurs in the fuction.