COM/MTS Guide - Prolifics

Defining the Component's InterfaceApplication DirectoryVersion NumberThe application directory will contain the COM component's DLL, its type library, andclient registry initialization file. Since the application needs to locate the server'sapplication library, place server.lib in this directory.For more information on files in the application directory, refer to page 5-2, “Createan Application Directory.”You can provide a version number for the component. At runtime, a client applicationcan ask for a specific version of a component; asking for the component without aversion number gets the latest version.When you append new methods or properties to the component, you can update theversion number (without generating a new CLSID). You can then register the newversion of the component on the server. The old entry is still in the registry for clientscalling for the old version, but since all versions have the same CLSID, all versions ofthe component will use the new DLL.Figure 3-5 By having both entries in the registry, application clients calling forversion 1 of the component can still access it, even though there are new methodsor properties.COM/MTS Guide 3-11