Real World XML Web Services: For VB and VB .NET Developers

4.5. Using WSDL Documents

In this section I will show you how to read a Web service's WSDL document and create the SOAP request message to invoke the Web service. I will do this using three different Web services, two of which are live on the Web.

To simplify things, we will make the SOAP request messages using simple string concatenation and use MSXML.XMLHTTP to send the message using HTTP POST. You should never use string concatenation to form a SOAP request in a real production application. There are many problems with this approach, including how easy it is to end up with XML that's neither valid nor well-formed. This approach, however, works well for learning examples as it keeps the code very simple and lets you focus on the SOAP message ...