Introduction

The Windows Communication Foundation, which was code-named Indigo, is a technology by which pieces of software can communicate with one another. There are many other such technologies, including COM and DCOM, RMI, MSMQ, and WebSphere MQ. Each of those works well in a particular scenario, not so well in others, and is of no use at all in some cases. The Windows Communication Foundation is meant to work well in any circumstance in which software entities must be made to communicate with one another. In fact, it is meant to always be the very best option: It provides performance that is about as good as, if not better than, any other alternative; it offers at least as many features and probably several more; and it will certainly always be the easiest solution to program.

Concretely, the Windows Communication Foundation consists of several new sets of classes added to the second version, the 2.0 version, of the Microsoft .NET Framework Class Library: principally, the Service Model, the Channel Layer, the XML Formatter, and the Extensible Security Infrastructure. It also adds some facilities for hosting Windows Communication Foundation solutions to Internet Information Services (IIS), the Web server that is built into Windows operating systems.

The Windows Communication Foundation will be released concurrently with the Windows Vista operating system in the second half of 2006, as part of a package called WinFX. WinFX includes several other technologies, including the Windows Presentation Foundation, which was code-named Avalon, the Windows Workflow Foundation, and InfoCard. Interim releases of WinFX, which are updated every month or two, can be downloaded from the Microsoft Windows Vista Developer center, at http://msdn.microsoft.com/winfx/. Those interim releases are available free, and so too will be the finished version.

One can install the Windows Communication Foundation on any Windows operating system on which the 2.0 version of the .NET Framework is supported. Those include Windows XP Service Pack 2, Windows Server 2003, Windows Server 2003 R2, Windows Vista, and the successor to Windows Server 2003, which is code-named Windows Longhorn Server. A very small number of features will be available only on Windows Vista and later operating systems.

Because the Windows Communication Foundation is meant to accommodate any circumstance in which software entities must be made to communicate with one another, it has a considerable number of features. However, the design of the Windows Communication Foundation makes it easy to understand how they all relate to one another. Nonetheless, this book is not intended to serve as an encyclopedic reference to the technology. Instead, it is meant to provide the understanding and knowledge required for most practical applications of the Windows Communication Foundation.

The book is written so as to explain the Windows Communication Foundation while showing how to use it. So, in each chapter, there are the precise steps for building a solution that demonstrates a particular aspect of the technology, along with a thorough explanation of each step. Readers who can program in C#, and who like to learn by doing, will be able to follow the steps. Those who prefer to just read will get a detailed account of the features of the Windows Communication Foundation, and be shown how to use them.

To follow the steps in the chapters, one should have any version of Visual Studio 2005 installed. Free copies are available at http://msdn.microsoft.com/vstudio/express/.

The January Community Technology Preview (CTP) Release of WinFX is also required. The instructions in the chapters assume that all the runtime and developer components of WinFX have been installed. The set of components may vary from one release of WinFX to another. The components of the current pre-release version of WinFX are clearly enumerated on the downloads page that is accessible from http://msdn.microsoft.com/winfx/.

A most important component of WinFX is the pertinent material in the Microsoft Windows Software Development Kit (SDK). By default, the SDK material installs into a folder called Microsoft SDKs\Windows in one's Program Files folder. Somewhere below that folder, one should find an archive called AllSamples.zip. That archive is usually located, by default, in the v1.0\samples subfolder. The archive contains a large number of Windows Communication Foundation samples.

Starting points for the solutions built in each of the chapters are available on this book's companion web page (www.samspublishing.com). Because the first version of the Windows Communication Foundation had yet to be completed at the time of writing, the authors pledge to keep providing updates to the text and the code via one of the author's Web logs at http://blogs.msdn.com/craigmcmurtry/archive/category/11914.aspx.

Many people contributed to this book. Among them are the folks on the Windows Communication Foundation development team, who were not actually aware they were contributing to a book. The reason is that the authors did not know, at the time they were doing the research, that they were, in fact, writing a book. What they produced just happened to be one.

The authors would like to thank Joe Long, Eric Zinda, Angela Mills, Omri Gazitt, Steve Swartz, Steve Millet, Mike Vernal, Doug Purdy, Eugene Osvetsky, Daniel Roth, Ford McKinstry, Craig McLuckie, Alex Weinert, Shy Cohen, Yasser Shohoud, Kenny Wolf, Anand Rajagopalan, Jim Johnson, Andy Milligan, Steve Maine, Ram Pamulapati, Ravi Rao, Andy Harjanto, T. R. Vishwanath, Doug Walter, Martin Gudgin, Giovanni Della-Libera, Kirill Gavrylyuk, Krish Srinivasan, Mark Fussell, Richard Turner, Ami Vora, Ari Bixhorn, Vic Gundotra, Neil Hutson, Steve DiMarco, Gianpaolo Carraro, Steve Woodward, James Conard, Vittorio Bertocci, Blair Shaw, Jeffrey Schlimmer, Matt Tavis, Mauro Ottoviani, John Frederick, Mark Renfrow, Sean Dixon, Matt Purcell, Cheri Clark, Mauricio Ordonez, Neil Rowe, Donovan Follette, Pat Altimore, Tim Walton, Manu Puri, Ed Pinto, Suwat Chitphakdibodin, Gowind Ramanathan, Ralph Squillace, John Steer, Brad Severtson, Gary Devendorf, and Al Lee. Any mistakes in the pages that follow are not their fault. The authors also owe a great debt of gratitude to their wives, Marta MacNeill, Kathryn Mercuri, and Sylvie Watling.