The TBN_TOOLBARCHANGE notification message notifies the toolbar’s parent
window that the user has customized a toolbar. This message is sent in the
form of a WM_NOTIFY message.
TBN_TOOLBARCHANGE
pnmhdr = (NMHDR FAR *) lParam;
Parameters
pnmhdr
Pointer to an NMHDR structure that contains information about the
notification message.