Beginning Web Development, Silverlight, and ASP.NET AJAX

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CHAPTER 7 ■ .NET 3.0: WINDOWS COMMUNICATION FOUNDATION
Creating an Address Service in WCF
In this section, you’ll look at what it takes to create an address service similar to that in
earlier chapters. However, as this is a WCF service, you’ll be able to take it to the next level
with some simple configuration changes—for example, adding reliability, security, and
transactable characteristics to it.
First, create the service using the WCF Service template in the File – New dialog.
Next, add a new DataSet to it. The DataSet should be based on the following SQL, which
makes a parameterized query against the database, filtering the addresses by the ZIP
code associated with it. Here’s the SQL:
SELECT
FROM
WHERE
AddressLine1, City, PostalCode
Person.Address
(PostalCode = @ZIP)
Chapter 5 shows the steps required to add this DataSet, if you aren’t already familiar
with it. You’ll be using the same DataSet here as you used in that chapter when you created
a web service.
The first thing you’ll need to do is create the interface that defines your service contract.
In the Chapter 5 web service, you passed an XmlDocument type, which is a complex
object requiring some pretty sophisticated data contracts to be set up in order to use it.
For the sake of simplicity in this example, you’ll instead pass a string. As a string is a
simple data type, you don’t need to define a data contract for it.
However, you’ll still need the ServiceContract to define the interface, and an
OperationContract to define the methods that are consumable by a client. Here’s
the code:
[ServiceContract()]
public interface IAddressService
{
[OperationContract]
string GetAddresses(string strZIP);
}
Next, you build your class that implements this interface. This class will also implement
the specified operation (GetAddresses).
First, here’s the class description:
public class AddressService : IAddressService
{
}