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plumbing (endpoints, binding, addresses, etc.). The obvious problem with this approach is that if

you need to change the plumbing details, you will be required to recode, recompile, and redeploy a

number of assemblies. Using a *.config file keeps your code base much more flexible, as changing

the plumbing is as simple as updating the file’s content and restarting the application.

The ABCs of WCF

Hosts and clients communicate with each other by agreeing on the ABCs, a friendly mnemonic for

remembering the core building blocks of a WCF application, specifically 

address, binding, and

contract.

•

Address: The location of the service. In code, this is represented with a System.Uri type;

however, the value is typically stored in *.config files.

•

Binding: WCF ships with a number of different bindings that specify network protocols,

encoding mechanisms, and the transport layer.

• Contract: A description of each method exposed from the WCF service.

Do understand that the ABC abbreviation does not imply that a developer must define the

address first, followed by binding, and ending with the contract. In many cases, a WCF developer

begins by defining a contract for the service, followed by establishing an address and bindings (but

any order will do, so long as each aspect is accounted for). Before we build our first WCF applica-

tion, here is a more detailed walk-through of the ABCs.