When working with the web services in a .NET environment, you can either generate the XML by using the Microsoft SOAP Toolkit to create low level routines, or you can use the WSDL tool to generate proxy classes.
Toolkits such as the Microsoft SOAP Toolkit provide low-level APIs for generating and exchanging SOAP messages. These APIs allow you to specify an XML document that represents the body of a SOAP message and send the document to the web service URL and returns the reply document as part of the SOAP message. This is a low-level interaction with the web services. This type of interaction allows the most flexibility because the web service interface does not change, even if the XML schema changes.
The disadvantage to by using the web service this way is that you must generate XML messages and deal with low-level APIs for sending and receiving SOAP messages. In this case, the WSDL is used only for specifying the endpoint URL of the web service.
To create XML and SOAP requests, you can write a web service client that uses a WSDL utility. A WSDL utility can automatically process your XML and SOAP requests and responses by representing them as proxy classes. Microsoft provides a WSDL utility that can represent XML documents as C# proxy classes.
To write an application that uses the classes generated by Microsoft .NET's WSDL utility, follow these steps:
