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Binding to ADO.NET Data Service

Updated on Sep 23, 2026

The purpose of this tutorial is to show you how to populate a RadComboBox with data from an ADO.NET Data Service in two ways:

Using plain methods call in the code-behind
Using MVVM approach

This tutorial uses the Northwind database.

Before proceeding further with this tutorial you need to create a new application and a RadComboBox declaration in your XAML.

XAML

<telerik:RadComboBox x:Name="radComboBox"/>

Using Plain Methods Call in the Code-Behind

Add a reference to your ADO.NET Data Service.
Switch to the code-behind and add a reference to the NorthwindEntities object.
C#
```
NorthwindEntities dbContext = new NorthwindEntities(new Uri("Enter your service address here"));
```
VB.NET
```
Dim dbContext As New NorthwindEntities(New Uri("Enter your service address here"))
```
For more information about how to add a reference to an ADO.NET Data Service and how to create a new instance of the exposed entity, take a look at the Consuming ADO.NET Data Service topic.

The ComboBoxs control will be populated with all Products from the Northwind database. In the drop-down list the ProductName and the UnitPrice properties will be displayed. Add the following code which will make the initial load of the objects.

private void BeginRequest()
{
    DataServiceQuery<Products> query = dbContext.CreateQuery<Products>("Products");
    query.BeginExecute(RequestCompleted, query);
}

private void RequestCompleted(IAsyncResult asyncResult)
{
    DataServiceQuery<Products> query = asyncResult.AsyncState as DataServiceQuery<Products>;
    var products = query.EndExecute(asyncResult).ToList();
    this.radComboBox.ItemsSource = products;
}

VB.NET

Private Sub BeginRequest()
	Dim query As DataServiceQuery(Of Products) = dbContext.CreateQuery(Of Products)("Products")
	query.BeginExecute(RequestCompleted, query)
End Sub

Private Sub RequestCompleted(ByVal asyncResult As IAsyncResult)
	Dim query As DataServiceQuery(Of Products) = TryCast(asyncResult.AsyncState, DataServiceQuery(Of Products))
	Dim products = query.EndExecute(asyncResult).ToList()
	Me.radComboBox.ItemsSource = products
End Sub

this.radComboBox.ItemsSource = dbContext.Products.Execute();

VB.NET

Me.radComboBox.ItemsSource = dbContext.Products.Execute()

You need to declare a custom DataTemplate to determine how the items in the drop-down will look like. Add the following DataTemplate declaration in your XAML resources.

XAML

<UserControl.Resources>
    <DataTemplate x:Key="CustomItemTemplate">
        <StackPanel Orientation="Horizontal">
            <TextBlock Text="{Binding ProductName}"/>
            <TextBlock Text=" - "/>
            <TextBlock Text="{Binding UnitPrice}"/>
            <TextBlock Text=" $"/>
        </StackPanel>
    </DataTemplate>
</UserControl.Resources>

Find your RadComboBox declaration and set the just declared DataTemplate to its ItemTemplate property.
XAML
```
<telerik:RadComboBox ItemTemplate="{StaticResource CustomItemTemplate}"/>
```

The end result with the data fetched from the service

WPF RadComboBox Bound to Data from ADO.NET Data Service

Using MVVM Approach

This section will show you how to populate your RadComboBox control in a MVVM manner. The ComboBox will be bound to a data source object, that has a property Products. When the control is loaded all products from the Products table in the Northwind database are loaded asynchronously.

Create a new class named NorthwindDataSource.

public class NorthwindDataSource
{
    private static NorthwindEntities northwindEntity;

    public NorthwindDataSource()
    {
        northwindEntity = new NorthwindEntities(new Uri("Enter your service address here"));
        this.Products = new ObservableCollection<Products>();
    }

    public ObservableCollection<Products> Products
    {
        get;
        set;
    }
}

VB.NET

For Each p As Products In northwindEntity.Products.Execute()
	Me.Products.Add(p)
Next

Add a reference to your ADO.NET Data Service.
In the NorthwindDataSource class add a reference to an ObservableCollection of Product.

In the NorthwindDataSource class add a reference to the NorthwindEntities object:

public class NorthwindDataSource
{
    private static NorthwindEntities northwindEntity;

    public NorthwindDataSource()
    {
        northwindEntity = new NorthwindEntities(new Uri("Enter your service address here"));
        this.Products = new ObservableCollection<Products>();
    }

    public ObservableCollection<Products> Products
    {
        get;
        set;
    }
}

VB.NET

For Each p As Products In northwindEntity.Products.Execute()
	Me.Products.Add(p)
Next

Add the following code in the constructor of the NorthwindDataSource. It will make the initial load of all Products from the database:

public class NorthwindDataSource
{
    private static NorthwindEntities northwindEntity;

    public NorthwindDataSource()
    {
        northwindEntity = new NorthwindEntities(new Uri("Enter your service address here"));
        this.Products = new ObservableCollection<Products>();
    }

    public ObservableCollection<Products> Products
    {
        get;
        set;
    }
}

VB.NET

For Each p As Products In northwindEntity.Products.Execute()
	Me.Products.Add(p)
Next

public class NorthwindDataSource
{
    private static NorthwindEntities northwindEntity;

    public NorthwindDataSource()
    {
        northwindEntity = new NorthwindEntities(new Uri("Enter your service address here"));
        this.Products = new ObservableCollection<Products>();
    }

    public ObservableCollection<Products> Products
    {
        get;
        set;
    }
}

VB.NET

For Each p As Products In northwindEntity.Products.Execute()
	Me.Products.Add(p)
Next

public class NorthwindDataSource
{
    private static NorthwindEntities northwindEntity;

    public NorthwindDataSource()
    {
        northwindEntity = new NorthwindEntities(new Uri("Enter your service address here"));
        this.Products = new ObservableCollection<Products>();
    }

    public ObservableCollection<Products> Products
    {
        get;
        set;
    }
}

VB.NET

For Each p As Products In northwindEntity.Products.Execute()
	Me.Products.Add(p)
Next

Declare the NorthwindDataSource object as a resource in your application.

XAML

<telerik:RadComboBox
        	ItemsSource="{Binding Source={StaticResource DataSource}, Path=Products}"
        	ItemTemplate="{StaticResource CustomItemTemplate}"/>

Declare a custom DataTemplate to determine how the items in the drop-down will look like.

XAML

<telerik:RadComboBox
        	ItemsSource="{Binding Source={StaticResource DataSource}, Path=Products}"
        	ItemTemplate="{StaticResource CustomItemTemplate}"/>

Update your RadComboBox declaration - set the ItemsSource and ItemTemplate properties.

XAML

<telerik:RadComboBox
        	ItemsSource="{Binding Source={StaticResource DataSource}, Path=Products}"
        	ItemTemplate="{StaticResource CustomItemTemplate}"/>

The end result with the data fetched from the service

WPF RadComboBox Bound to Data from ADO.NET Data Service

Binding to ADO.NET Data Service

Using Plain Methods Call in the Code-Behind

Using MVVM Approach

See Also