XML Web Services Using ASP.NET 

Building a simple Web service using ASP.NET is relatively easy and is covered in ASP.NET XML Web Service Basics and Walkthrough: Building a Basic XML Web Service Using ASP.NET. However, the true power of Web services is realized when you look at the infrastructure. Web services are built on top of the .NET Framework and the common language runtime. A Web service can take advantage of these technologies. For instance, the performance, state management, and authentication supported by ASP.NET can all be taken advantage of by building Web services using ASP.NET.

The infrastructure for Web services is built to conform to industry standards such as SOAP, XML, and WSDL, and this allows clients from other platforms to interoperate with Web services. As long as a client can send standards-compliant SOAP messages, formatted according to a service description, that client can call a Web service created using ASP.NET (regardless of the platform on which the client resides). For more information on how ASP.NET provides an attribute-based mechanism for modifying the format of the expected SOAP, see Customizing SOAP Message Formatting.

When you build a Web service using ASP.NET, it automatically supports clients communicating using the SOAP, HTTP-GET, and HTTP-POST protocols. Since HTTP-GET and HTTP-POST support passing messages in URL-encoded name-value pairs, the data type support for these two protocols is not as rich as that supported for SOAP. In SOAP, which passes data to and from the Web service using XML, you can define complex data types using XSD schemas, which support a richer set of data types. Developers building a Web service using ASP.NET do not have to explicitly define complex data types they expect using an XSD schema. Rather, they can simply build a managed class. ASP.NET handles mapping class definitions to an XSD schema and mapping object instances to XML data in order to pass it back and forth across a network.

It is important to note that Web services are not a replacement for DCOM, but rather a messaging infrastructure for communicating across platforms using industry standards.

In This Section

• ASP.NET XML Web Service Basics
  Explains the basic behavior of ASP.NET Web services.

• Walkthrough: Building a Basic XML Web Service Using ASP.NET
  Explains the basic steps for creating Web services using ASP.NET.

• Asynchronous XML Web Service Methods
  Explains the basic behavior of asynchronous methods in ASP.NET Web services.

• How to: Create Asynchronous Web Service Methods
  Describes how to create an asynchronous Web service using ASP.NET.

• How to: Chain Asynchronous Calls with a Web Service Method
  Provides a code example where a Web service method makes more than one asynchronous call and the calls must execute sequentially.

• How to: Manage State in Web Services Created Using ASP.NET
  Explains how to manage state in ASP.NET Web services.

• Transactions in ASP.NET XML Web Services
  Explains how ASP.NET Web services manage transactions.

• How to: Participate in Transactions in Web Services Created Using ASP.NET
  Details how to add transaction support to a Web service created using ASP.NET.

• HTML Parsing by ASP.NET XML Web Services
  Explains how ASP.NET Web services parse Web pages to deliver XML content.

• How to: Create Web Services That Parse the Contents of a Web Page
  Explains how to create a Web service that parses the contents of an existing Web page and exposes the contents as programmable elements.

• Securing XML Web Services Created Using ASP.NET
  Explains how authentication and authorization work for ASP.NET Web services.

• How to: Perform Custom Authentication Using SOAP Headers
  Shows how to use an HTTP Module to check the contents of a SOAP header for authentication information.

• XML Web Services Using ASP.NET
  Shows how to configure and pass client credentials to a Web service using Windows authentication.

• XML Web Services Publishing and Deployment
  Walks through the steps for publishing and deploying a Web service created using ASP.NET.

• Design Guidelines for XML Web Services Created Using ASP.NET
  Outlines several best practices for creating Web services using ASP.NET.

Related Sections

• XML Web Services Overview
  Provides a platform-neutral overview of XML Web services.

• Building XML Web Service Clients
  Details how to build a client to an XML Web service, regardless of the platform or technology used to build the XML Web service.

• Handling and Throwing Exceptions in XML Web Services
  Describes how to handle exceptions from an XML Web service created using ASP.NET and XML Web service clients created using the .NET Framework.

• Using SOAP Headers
  Details how SOAP headers can be defined, processed, and manipulated for clients calling XML Web services created using ASP.NET.

• Customizing SOAP Message Formatting
  Describes how to control the SOAP sent to and from XML Web services created using ASP.NET.

• SOAP Message Modification Using SOAP Extensions
  Explains how to build extensions that modify the SOAP messages sent across the network for XML Web services created using ASP.NET and their clients.