Introduction

Title: Introduction to COM using C++

This 2-day course is intended to give students an introduction to COM in anticipation of DCOM.

Prerequisites

This course assumes that you have a good knowledge of programming using C++

Description

This course emphasizes the merits and fundamentals programming using C++. It starts out with identifying the problems with client-server software on the internet such as version independence, CPU vendor independence, OS vendor independence, application vendor independence and so on... The remainder of the course identifies how COM and DCOM solve these problems.

Learning Objectives

	Identify the merits and perils of COM
	Learn how to create basic COM clients and servers with and without the ATL Wizard

Course Duration: 2 days

Topics

Introduction to COM

	The Intranet problem
	The Intranet solutions: RPC, CORBA, COM & Java
	How does DCOM solve the Intranet problem?

Internationalization

Problem: Too many alphabets

Solutions

	Unicode
	Same source code for Unicode v. ANSI
	Converting ANSI to/from Unicode and back

Fundamentals of COM

Version independence

New clients call old servers (and vice versa)

	NO recompilation
	NO relinking

Language independence

	Platform independence
	Distributed COM (DCOM)
	How do COM applications achieve this independence?

COM Client Programming

COM Interfaces

	Perils & merits of custom COM interfaces
	Basic concepts: usage counts, ProgID, CLSID
	Create a COM client

Microsoft implementations

	Automation: IDispatch
	Storing object: IStorage, IStream & ILockBytes
	Object Linking: IMoniker
	ClipBoard: IDataObject

COM Server Programming

Introduction

Three different approaches

	ATL (ActiveX Template Library)
	MFC & AppWizard
	Write the code yourself

Registering DLL COM servers

GUIDGEN

COM replacements for new

	CoCreateInstance
	Class factories classes

EXE servers v. DLL servers

Writing DLL Servers