Programming ASP.NET, 3rd Edition

Creating a Simple Web Service

Though a web service has no user interface and no visual component, the architecture and files used to create a web service are similar to those used to create a web page, which are described in detail in previous chapters. Some of these similarities include the following:

• Full implementation of the .NET Framework and Common Language Runtime (CLR), including the object-oriented architecture, all the base class libraries, and features such as caching, state, and data access

• Nearly identical file and code structures

• All source code files in plain text, which can be created in any text editor

• Full support by VS2005, with all its productivity features, including IntelliSense, code completion, and integrated debugging

• Configurable on a global or application-wide basis using plain-text configuration files and the Web Site Administration Tool in VS2005

That said, web pages and web services are conceptually very different. A web page entails an interface designed for interaction with a person sitting at a web browser. A web service, on the other hand, consists only of methods, some of which are available for remote calls by client applications.

A web service can be coded in-line, in a single file with an extension of .asmx. Alternatively, the application logic of the web service can be segregated into a code-behind file, which is the default behavior of VS2005. One in-line example will be shown here, to aid in your understanding of how web services work, but all the ...