Professional Visual Basic® 2010 and .NET 4

Chapter 13. Services (XML/WCF)

WHAT YOU WILL LEARN IN THIS CHAPTER

• Review of distributed communication technologies

• Introduction to Web services and remoting

• Overview of service-oriented architecture

• WSDL, SOAP and WS-* protocols

• Creating a WCF service

• Creating a WCF TCP host

• Creating a WCF client

• Testing a WCF service with Visual Studio over HTTP

• Creating a WCF client with a data contract

• Testing a WCF service over TCP

Over the years there has been an ongoing effort to make communication between distributed components as easy as communication between components and objects within a single executable. Microsoft's first foray into distributed computing involved a technology known as Distributed COM (DCOM). With the introduction of .NET, Microsoft replaced COM, and by extension DCOM, with two new emergent technologies: ASP.NET Web Services and .NET Remoting.

Most people recognized Remoting as the next generation of DCOM, as it was primarily a binary protocol tied to a Microsoft implementation. As such, its use was limited in a heterogeneous environment, which limited adoption. Conversely, XML Web services proved to be a more emergent technology, one which has continued to evolve, changing the face of distributed computing.

However, the initial release of XML Web Services (known within the .NET community as ASP.NET Web Services), didn't have sufficient support for advanced security and related features that were built into binary protocols like Remoting.

Thus, in the .NET 2.0 time frame you could ...