... see sev-eral examples of the creating of messages and the dispatching of these messagesboth by the object that created them and by other objects.Figure 9-1 . The inheritance hierarchy for the ... messages of these applica-tion-defined types, add data to these messages, and then pass the messages on toother object or even other applications.Message HandlingAn application-defined message ... NULL) The first parameter, message, is the BMessage object to post. The second parame-ter, handler, names the target handler the BHandler object to which the mes-sage is to be delivered. The...