101 Microsoft® Visual Basic® .NET Applications

Application #50. Expose a Simple Web Service

You now begin another three-part series on Web-application development. In this topic, you’ll learn how to build an XML Web service that exposes two methods. One method returns an untyped DataSet of the ten most expensive products from the Northwind database. The other, more complex, method returns an instance of a custom class containing a typed DataSet of products ordered by a customer, as well as the company name.

The Framework automatically renders a Web service test user interface when you load a Web service page (.asmx) in a browser. When the page first loads, you’re presented with a list of links to the methods offered by the service. Clicking a link takes you to the method’s test interface, ...