with this code:

When the Web server side of the Silverlight project is wired, configure the Silverlight application itself to consume the data exposed by the LinqToSql service. The following sections take you through the process of referencing the WCF service and binding the SQL data to a DataGrid control.

The first step in accessing the SQL data from a Silverlight application is to add a reference to the IService1 Web service. This is done by right-clicking the References folder in the Silverlight project and selecting Add Service Reference from the drop-down list to display the Add Service Reference dialog box, as shown in Figure 15.13. Click Discover to find the Service 1.svc service. Expand the link, as shown in Figure 15.13. The Contract you defined in the IService.cs file should be listed in the Operations list. Select the IService1 service and click OK to add the ServiceReference1 reference.

Now you need to create a Silverlight control that can consume the data from the LINQ query. One of the best options is a DataGrid because it naturally conforms to database-style data. Add the following code to the UserControl of the Page.xaml file shown in Listing 15.11 to add the Data namespace:

Then add a DataGrid contol with the appropriate settings for your application, as shown in Listing 15.11. Implement a TextBox and Button control that are used to send the string to query against the database to the data service, as shown in Listing 15.11.

The code in Listing 15.12 implements managed code that attaches an event handler to the Button control to initiate access to the data service. First, attach a Click event handler to the Button control using code similar to the following:

SearchBtn.Click += new RoutedEventHandler(doSearch);

Then, inside the Click event handler doSearch(), create a ServiceClient object wService using the ServiceReference1 service reference as shown in the following code:

ServiceReference1.Service1Client wService = new DataLinqApp.ServiceReference1.Service1Client();

The communication between the Silverlight application and the data service needs to be asynchronous so that the Silverlight interface is still responsive while waiting for the Web service to respond. This is done by attaching a completed event handler to the ServiceClient object. Use the following code, shown in Listing 15.12, to attach a GetMoviesByTitleCompleted event handler to the wService object. This event is triggered when the GetMoviesByTitle request is completed:

wService.GetMoviesByTitleCompleted += new EventHandler<DataLinqApp.ServiceReference1. GetMoviesByTitleCompletedEventArgs>(getMoviesDone);

When the completed event handler is attached, you can add an asynchronous call to the GetMoviesByTitle operation of the data service using the following code:

wService.GetMoviesByTitleAsync(titleSearch.Text);

The value of the titleSearch Textbox is passed in as the search parameter to the service. The last thing you need to do is add the completed event handler for the GetMoviesByTitleCompleted event as shown in the following code:

void getMoviesDone(object sender, DataLinqApp.ServiceReference1.GetMoviesByTitleCompletedEventArgs e) { movieGrid.ItemsSource = e.Result;

Inside the getMoviesDone() event handler, shown in Listing 15.12, the result from the GetMoviesByTitleAsync request is bound to the movieGrid control using the ItemsSource attribute. The results of the code in Listings 15.9, 15.10, 15.11, and 15.12 of the DataLinqApp are shown in Figure 15.14. When the user types a string in Search text box and clicks Search, the database is queried using a LINQ query and the results appear in the DataGrid control.

using using using using using System; System.Collections.Generic; System.Linq; System.Runtime.Serialization; System.ServiceModel;

using System.Text; namespace DataLinqApp_Web { [ServiceContract] public interface IService1 { [OperationContract] List<Movie> GetMoviesByTitle(string mTitle); }

using using using using using using System; System.Collections.Generic; System.Linq; System.Runtime.Serialization; System.ServiceModel; System.Text;

namespace DataLinqApp_Web { public class Service1 : IService1 { public List<Movie> GetMoviesByTitle(string mTitle) { DataClasses1DataContext db = new DataClasses1DataContext(); var movies = from m in db.Movies where m.Title.Contains(mTitle) select m; return movies.ToList(); } } }