fsCmd (USHORT)
This field contains a flag to indicate what action is to be performed:
QFC_NEXTINCHAIN
The hwndParent parameter is not used.
The window handle returned is a child of the window specified by the hwndParent parameter.
The hwndParent parameter is not used.
Return NULL, if no window in the owner group has had the focus.
The hwndParent parameter is not used.
Because this message is passed along the focus chain, this is equivalent to returning TRUE, if the handle of the window receiving this message is hwndParent or to returning FALSE, if it is not.
hwndParent (HWND)
hwndResult (HWND)
This value is also to be interpreted as FALSE for the case when the fsCmd is set to QFC_PARTOFCHAIN.
Other
This value is also to be interpreted as TRUE for the cases when the fsCmd is set to QFC_PARTOFCHAIN.