LB_SETSEL
wParam = (WPARAM) (BOOL) fSelect; /* selection flag */
lParam = MAKELPARAM(index, 0); /* item index */
An application sends an LB_SETSEL message to select a string in a multiple-selection list box.
fSelect
Value of wParam. Specifies how to set the selection. If the fSelect parameter is TRUE, the string is selected and highlighted; if fSelect is FALSE, the highlight is removed and the string is no longer selected.
index
Value of the low-order word of lParam. Specifies the zero-based index of the string to set. If the index parameter is –1, the selection is added to or removed from all strings, depending on the value of fSelect.
The return value is LB_ERR if an error occurs.
This message should be used only with multiple-selection list boxes.