Select Data Using Silverlight RIA Enabled Service

Introduction

Today, in this article let's play around with one of the interesting and most useful concepts in Silverlight.

Question: What is select data using Silverlight RIA enabled service?

In simple terms "This application enables selection of data in the database with help of a Silverlight RIA enabled service. It uses a base platform of Entity Framework to communicate with the database".

Step 1: Create a database named "Company" with employee table in it.

Step 2: Open up Visual Studio and create a new Silverlight application enabled with RIA Services

Step 3: When the project is created. Right-click on the RIA Service project and add a new entity data model framework and set it up for the previously created database.

Step 4: Again right-click on the RIA service project and add a Domain Service Class as a new item.

Step 5: The complete code of EmployeeDomain.cs looks like this (Domain Service Class):

namespace SilverlightRIASelectApp.Web

{

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.ComponentModel.DataAnnotations;

using System.Data;

using System.Linq;

using System.ServiceModel.DomainServices.EntityFramework;

using System.ServiceModel.DomainServices.Hosting;

using System.ServiceModel.DomainServices.Server;

// Implements application logic using the CompanyEntities context.

// TODO: Add your application logic to these methods or in additional methods.

// TODO: Wire up authentication (Windows/ASP.NET Forms) and uncomment the following to disable anonymous access

// Also consider adding roles to restrict access as appropriate.

// [RequiresAuthentication][EnableClientAccess()]

public class EmployeeDomain : LinqToEntitiesDomainService<CompanyEntities>

{

// TODO:// Consider constraining the results of your query method. If you need additional input you can

// add parameters to this method or create additional query methods with different names.

// To support paging you will need to add ordering to the 'Employee'

query.public IQueryable<Employee> GetEmployee()

{

return this.ObjectContext.Employee;

}

public void InsertEmployee(Employee employee)

{

if ((employee.EntityState != EntityState.Detached))

{

this.ObjectContext.ObjectStateManager.ChangeObjectState(employee, EntityState.Added);

}

else

{

this.ObjectContext.Employee.AddObject(employee);

}

public void UpdateEmployee(Employee currentEmployee)

{

this.ObjectContext.Employee.AttachAsModified(currentEmployee, this.ChangeSet.GetOriginal(currentEmployee));

}

public void DeleteEmployee(Employee employee)

{

if ((employee.EntityState != EntityState.Detached))

{

this.ObjectContext.ObjectStateManager.ChangeObjectState(employee, EntityState.Deleted);

}

else

{

this.ObjectContext.Employee.Attach(employee);

this.ObjectContext.Employee.DeleteObject(employee);

}

Step 6: Now rebuild the solution file.

Step 7: the Complete code of MainPage.xaml looks like this:

<usercontrolx:class="SilverlightRIASelectApp.MainPage"xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"xmlns:d="http://schemas.microsoft.com/expression/blend/2008"

xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"mc:ignorable="d"

d:designheight="300"d:designwidth="400"xmlns:sdk="http://schemas.microsoft.com/winfx/2006/xaml/presentation/sdk">

<Gridx:Name="LayoutRoot"Background="White">

<sdk:DataGridHeight="216"HorizontalAlignment="Left"Margin="57,57,0,0"Name="dataGrid1"VerticalAlignment="Top"Width="254"/>

<ButtonContent="Show Data"Height="23"HorizontalAlignment="Left"Margin="158,14,0,0"Name="button1"VerticalAlignment="Top"Width="75"Click="button1_Click"/>

</Grid>

</usercontrol>

Step 8: The complete code of MainPage.xaml.cs looks like this:

using System;

using System.Collections.Generic;

using System.Linq;

using System.Net;

using System.Windows;

using System.Windows.Controls;

using System.Windows.Documents;

using System.Windows.Input;

using System.Windows.Media;

using System.Windows.Media.Animation;

using System.Windows.Shapes;

using SilverlightRIASelectApp.Web;

using System.ServiceModel.DomainServices.Client;

namespace SilverlightRIASelectApp

{

public partial class MainPage : UserControl

{

public MainPage()

{

InitializeComponent();

}

EmployeeDomain objDomain = new EmployeeDomain();

private void button1_Click(object sender, RoutedEventArgs e)

{

LoadOperation<Employee> load = objDomain.Load(objDomain.GetEmployeeQuery());

dataGrid1.ItemsSource = load.Entities;

}

Step 9: Output of the application looks like this:

Step 10: Data showing output of application looks like this:

I hope this article is useful for you.