21.4. Working with Data Sources
At the beginning of the chapter you created a strongly typed DataSet that contains a number of rows from the Contact table, based on a Title parameter. The DataSet is contained within a class library, ContactDataAccess, that you are going to expose to your application via a web service. To do this, you need to add a Windows application, ContactBrowser, and an ASP.NET web service application, ContactServices, to your solution. This demonstrates how you can use Visual Studio 2008 to build a true multi-tier application
Because this section involves working with ASP.NET applications, it is recommended that you run Visual Studio 2008 in Administrator mode if you are running Windows Vista. This will allow the debugger to be attached to the appropriate process.
In the Web Service project, you will add a reference to the class library. You also need to modify the Service class file so it has two methods, in place of the default HelloWorld web method:
Imports System.Web.Services Imports System.Web.Services.Protocols Imports System.ComponentModel Imports ContactDataAccess <System.Web.Services.WebService(Namespace:="http://tempuri.org/")> _ <System.Web.Services.WebServiceBinding(ConformsTo:=WsiProfiles.BasicProfile1_1)> _
<ToolboxItem(False)> _ Public Class Service Inherits System.Web.Services.WebService <WebMethod()> _ Public Function RetrieveContacts(ByVal Title As String) _ As AdventureWorksDataSet.ContactDataTable Dim ta As New AdventureWorksDataSetTableAdapters.ContactTableAdapter ...