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DataServiceCollection<T> Class

Represents a dynamic entity collection that provides notifications when items get added, removed, or when the list is refreshed.

Namespace:  System.Data.Services.Client
Assembly:  System.Data.Services.Client (in System.Data.Services.Client.dll)

public class DataServiceCollection<T> : ObservableCollection<T>

Type Parameters


An entity type.

This topic describes new functionality in ADO.NET Data Services that is available as an update to the .NET Framework version 3.5 Service Pack 1. You can download and install the update from the Microsoft Download Center.

ADO.NET Data Services provides the DataServiceCollection<T> class to support binding data to controls in client applications. This class inherits from the ObservableCollection<T> class, which implements the INotifyCollectionChanged interface and is the primary data binding mechanism for Windows Presentation Foundation (WPF) and Silverlight-based applications.

You can load an ObservableCollection<T> binding collection by using any collection that implements the IEnumerable<T> interface. Items loaded into the binding collection must implement the INotifyPropertyChanged interface. For more information, see Binding Data to Controls (ADO.NET Data Services).

The following example is from the code-behind page for an Extensible Application Markup Language (XAML) page that defines the SalesOrders window in WPF. When the window is loaded, an DataServiceCollection<T> is created based on the result of a query that returns customers with related objects, filtered by country. This result is bound to the DataContext property of the StackPanel that is the root layout control for the WPF window.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using System.Data.Services.Client;
using NorthwindModel;

namespace NorthwindClient
    public partial class CustomerOrdersWpf : Window
        private NorthwindEntities context;
        private DataServiceCollection<Customers> trackedCustomers;
        private const string customerCountry = "Germany";
        private const string svcUri = "http://localhost:12345/Northwind.svc/";

        public CustomerOrdersWpf()

        private void Window_Loaded(object sender, RoutedEventArgs e)
                // Initialize the context for the data service.
                context = new NorthwindEntities(new Uri(svcUri));

                // Create a LINQ query that returns customers with related orders.
                var customerQuery = from cust in context.Customers.Expand("Orders")
                                    where cust.Country == customerCountry
                                    select cust;

                // Create a new collection for binding based on the LINQ query.
                trackedCustomers = new DataServiceCollection<Customers>(customerQuery);

                // Bind the root StackPanel element to the collection; 
                // related object binding paths are defined in the XAML.
                LayoutRoot.DataContext = trackedCustomers;
            catch (DataServiceQueryException ex)
                MessageBox.Show("The query could not be completed:\n" + ex.ToString());
            catch (InvalidOperationException ex)
                MessageBox.Show("The following error occured:\n" + ex.ToString());
        private void saveChangesButton_Click(object sender, RoutedEventArgs e)
            // Save changes to the data service.

The following is the XAML that defines the SalesOrders window in WPF for the previous example.

<Window x:Class="NorthwindClient.SalesOrders"
    Title="Northwind Orders" Height="335" Width="425" 
        Name="OrdersForm" Loaded="OrdersForm_Loaded">
    <Grid Name="orderItemsGrid">
        <ComboBox DisplayMemberPath="SalesOrderID" ItemsSource="{Binding}"
                  Height="23" Margin="122,12,198,0" Name="comboBoxOrder" VerticalAlignment="Top"/>
        <ListView ItemsSource="{Binding Path=SalesOrderDetail}" Name="listViewItems" Margin="34,46,34,50">
                <GridView AllowsColumnReorder="False" ColumnHeaderToolTip="Line Items">
                    <GridViewColumn DisplayMemberBinding="{Binding Path=ProductID}" 
                        Header="Product" Width="50"/>
                    <GridViewColumn DisplayMemberBinding="{Binding Path=OrderQty}" 
                        Header="Quantity" Width="50"/>
                    <GridViewColumn DisplayMemberBinding="{Binding Path=UnitPrice}" 
                        Header="Cost" Width="50"/>
                    <GridViewColumn DisplayMemberBinding="{Binding Path=LineTotal}" 
                        Header="Line Total" Width="80"/>
        <Label Height="28" Margin="34,12,0,0" Name="orderLabel" VerticalAlignment="Top" 
               HorizontalAlignment="Left" Width="93">Order:</Label>
        <StackPanel Name="Buttons" Orientation="Horizontal" HorizontalAlignment="Right" >
        <Button Height="23" Margin="0,0,12,12" 
                Name="buttonClose" VerticalAlignment="Bottom" Width="75" Click="buttonClose_Click">Close</Button>
        <Button Height="23" HorizontalAlignment="Right" Margin="0,0,12,12" 
                Name="buttonSave" VerticalAlignment="Bottom" Width="75" Click="buttonSaveChanges_Click">Save Changes</Button>
<Window x:Class="NorthwindClient.CustomerOrdersWpf"
             Height="423" Width="679" Loaded="Window_Loaded">
    <StackPanel Orientation="Vertical" Height="Auto" Name="LayoutRoot" Width="Auto">
        <Label Content="Customer ID" Margin="20,0,0,0" />
        <ComboBox Name="customerIDComboBox" DisplayMemberPath="CustomerID" ItemsSource="{Binding}" 
                  IsSynchronizedWithCurrentItem="True" SelectedIndex="0" Height="23" Width="120" 
                  HorizontalAlignment="Left" Margin="20,0,0,0" VerticalAlignment="Center" />
        <ListView ItemsSource="{Binding Path=Orders}" Name="ordersDataGrid" Margin="34,46,34,50">
                <GridView AllowsColumnReorder="False" ColumnHeaderToolTip="Line Items">
                    <GridViewColumn DisplayMemberBinding="{Binding Path=OrderID}" 
                        Header="Order ID" Width="50"/>
                    <GridViewColumn DisplayMemberBinding="{Binding Path=OrderDate}" 
                        Header="Order Date" Width="50"/>
                    <GridViewColumn DisplayMemberBinding="{Binding Path=Freight}" 
                        Header="Freight Cost" Width="50"/>
        <Button Name="saveChangesButton" Content="Save Changes" Click="saveChangesButton_Click" 
                Width="80" Height="30" Margin="450,0,0,0"/>

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5 SP1