The file and stream handlers included with Windows use an object-oriented design to promote a standard interface and to share functionality. These handlers are written in C++ and use the OLE Component Object Model.
You can develop custom handlers using the C or C++ development systems; however, using C++ is strongly recommended, because it provides an easier and more straightforward approach to implement a handler. Using C++, you can explicitly define data as objects, and you can associate the functions that manipulate the data with the member functions of an object.
This section identifies and briefly summarizes the important concepts of C++ and the OLE Component Object Model that apply to designing and implementing file and stream handlers. There are many books written about C++ programming that you can reference for more information. For more information on OLE, please see the OLE Programmer's Reference.