Programming Visual Basic 2005

Creating a Web Service

There are two broad aspects to web service development: creating the web service and consuming the web service. You'll start by creating a simple web service that provides a simulated stock information service. Your web service will expose two methods:

    Function GetName(stockSymbol As String) as String
    Function GetPrice (stockSymbol As String) as Float

Tip

If this web service were an actual production program, the data returned would be fetched from a live database. In order not to confuse web service issues with data access issues, the data in this chapter will be stored in a two-dimensional array of strings.

Begin by creating a new web site named StockPriceWebService. Be sure to click on ASP.NET Web Service in the templates window, as shown in Figure 14-1.

Visual Studio 2005 does a lot of the work of setting up your web service, including adding the necessary <WebService> attributes to your class, and creating a template method (HelloWorld) complete with <WebMethod> attributes. For more on attributes, see the note on attributes in Chapter 12.

Figure 14-1. Creating a web service

You'll add a two dimensional array of stock symbols with their names and fictional prices, as shown in Example 14-1.

Example 14-1. Two-dimensional array of stock symbols and prices

Dim stocks As String(,) = _ { _ {"MSFT", "Microsoft", "25.22"}, _ {"DELL", "Dell Computers", "42.12"}, _ {"INTC", ...