DataServiceCollection<T> Class

Definition

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

generic <typename T>
public ref class DataServiceCollection : System::Collections::ObjectModel::ObservableCollection<T>
public class DataServiceCollection<T> : System.Collections.ObjectModel.ObservableCollection<T>
type DataServiceCollection<'T> = class
    inherit ObservableCollection<'T>
Public Class DataServiceCollection(Of T)
Inherits ObservableCollection(Of T)

Type Parameters

T

An entity type.

Inheritance
DataServiceCollection<T>

Examples

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/region. 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 NorthwindClient.Northwind;

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

        public CustomerOrdersWpf()
        {
            InitializeComponent();
        }

        private void Window_Loaded(object sender, RoutedEventArgs e)
        {
            try
            {
                // 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<Customer>(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 occurred:\n" + ex.ToString());
            }
        }
        private void saveChangesButton_Click(object sender, RoutedEventArgs e)
        {
            // Save changes to the data service.
            context.SaveChanges();
        }
    }
}
Imports System.Collections.Generic
Imports System.Linq
Imports System.Text
Imports System.Windows
Imports System.Windows.Controls
Imports System.Windows.Data
Imports System.Windows.Documents
Imports System.Windows.Input
Imports System.Windows.Media
Imports System.Windows.Media.Imaging
Imports System.Windows.Navigation
Imports System.Windows.Shapes
Imports System.Data.Services.Client
Imports NorthwindClient.Northwind

Partial Public Class CustomerOrdersWpf
    Inherits Window

    Private context As NorthwindEntities
    Private trackedCustomers As DataServiceCollection(Of Customer)
    Private Const customerCountry As String = "Germany"
    Private Const svcUri As String = "http://localhost:12345/Northwind.svc/"
    Private Sub Window_Loaded(ByVal sender As Object, ByVal e As RoutedEventArgs)
        Try
            ' Initialize the context for the data service.
            context = New NorthwindEntities(New Uri(svcUri))

            ' Create a LINQ query that returns customers with related orders.
            Dim 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(Of Customer)(customerQuery)

                ' Bind the root StackPanel element to the collection
                ' related object binding paths are defined in the XAML.
            Me.LayoutRoot.DataContext = trackedCustomers
        Catch ex As DataServiceQueryException
            MessageBox.Show("The query could not be completed:\n" + ex.ToString())
        Catch ex As InvalidOperationException
            MessageBox.Show("The following error occurred:\n" + ex.ToString())
        End Try
    End Sub
    Private Sub saveChangesButton_Click(ByVal sender As Object, ByVal e As RoutedEventArgs)
        ' Save changes to the data service.
        context.SaveChanges()
    End Sub
End Class

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

    <Window x:Class="CustomerOrdersWpf"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             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">
            <ListView.View>
                <GridView AllowsColumnReorder="False" ColumnHeaderToolTip="Line Items">
                    <GridViewColumn DisplayMemberBinding="{Binding Path=OrderID, Mode=OneWay}" 
                        Header="Order ID" Width="50"/>
                    <GridViewColumn DisplayMemberBinding="{Binding Path=OrderDate, Mode=TwoWay}" 
                        Header="Order Date" Width="50"/>
                    <GridViewColumn DisplayMemberBinding="{Binding Path=Freight, Mode=TwoWay}" 
                        Header="Freight Cost" Width="50"/>
                </GridView>
            </ListView.View>
        </ListView>
        <Button Name="saveChangesButton" Content="Save Changes" Click="saveChangesButton_Click" 
                Width="80" Height="30" Margin="450,0,0,0"/>
    </StackPanel>
</Window>

Remarks

WCF 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.

Constructors

DataServiceCollection<T>()

Creates a new instance of the DataServiceCollection<T> class.

DataServiceCollection<T>(DataServiceContext)

Creates a new instance of the DataServiceCollection<T> class that uses the specified DataServiceContext.

DataServiceCollection<T>(DataServiceContext, IEnumerable<T>, TrackingMode, String, Func<EntityChangedParams,Boolean>, Func<EntityCollectionChangedParams,Boolean>)

Creates a new instance of the DataServiceCollection<T> class a based on query execution, with the supplied change method delegates, and that uses the supplied DataServiceContext.

DataServiceCollection<T>(DataServiceContext, String, Func<EntityChangedParams,Boolean>, Func<EntityCollectionChangedParams,Boolean>)

Creates a new instance of the DataServiceCollection<T> class with the supplied change method delegates and that uses the specified DataServiceContext.

DataServiceCollection<T>(IEnumerable<T>)

Creates a new instance of the DataServiceCollection<T> class based on query execution.

DataServiceCollection<T>(IEnumerable<T>, TrackingMode)

Creates a new instance of the DataServiceCollection<T> class based on query execution and with the specified tracking mode.

DataServiceCollection<T>(IEnumerable<T>, TrackingMode, String, Func<EntityChangedParams,Boolean>, Func<EntityCollectionChangedParams,Boolean>)

Creates a new instance of the DataServiceCollection<T> class a based on query execution and with the supplied change method delegates.

Properties

Continuation

Gets a continuation object that is used to return the next set of paged results.

Count

Gets the number of elements actually contained in the Collection<T>.

(Inherited from Collection<T>)
Item[Int32]

Gets or sets the element at the specified index.

(Inherited from Collection<T>)
Items

Gets a IList<T> wrapper around the Collection<T>.

(Inherited from Collection<T>)

Methods

Add(T)

Adds an object to the end of the Collection<T>.

(Inherited from Collection<T>)
BlockReentrancy()

Disallows reentrant attempts to change this collection.

(Inherited from ObservableCollection<T>)
CheckReentrancy()

Checks for reentrant attempts to change this collection.

(Inherited from ObservableCollection<T>)
Clear()

Removes all elements from the Collection<T>.

(Inherited from Collection<T>)
Clear(Boolean)

Removes all items from the collection, and optionally detaches all the items from the DataServiceContext.

ClearItems()

Removes all items from the collection.

(Inherited from ObservableCollection<T>)
Contains(T)

Determines whether an element is in the Collection<T>.

(Inherited from Collection<T>)
CopyTo(T[], Int32)

Copies the entire Collection<T> to a compatible one-dimensional Array, starting at the specified index of the target array.

(Inherited from Collection<T>)
Detach()

Disables DataServiceContext tracking of all items in the collection.

Equals(Object)

Determines whether the specified object is equal to the current object.

(Inherited from Object)
GetEnumerator()

Returns an enumerator that iterates through the Collection<T>.

(Inherited from Collection<T>)
GetHashCode()

Serves as the default hash function.

(Inherited from Object)
GetType()

Gets the Type of the current instance.

(Inherited from Object)
IndexOf(T)

Searches for the specified object and returns the zero-based index of the first occurrence within the entire Collection<T>.

(Inherited from Collection<T>)
Insert(Int32, T)

Inserts an element into the Collection<T> at the specified index.

(Inherited from Collection<T>)
InsertItem(Int32, T)

Adds a specified item to the collection at the specified index.

Load(IEnumerable<T>)

Loads a collection of entity objects into the collection.

Load(T)

Loads a single entity object into the collection.

MemberwiseClone()

Creates a shallow copy of the current Object.

(Inherited from Object)
Move(Int32, Int32)

Moves the item at the specified index to a new location in the collection.

(Inherited from ObservableCollection<T>)
MoveItem(Int32, Int32)

Moves the item at the specified index to a new location in the collection.

(Inherited from ObservableCollection<T>)
OnCollectionChanged(NotifyCollectionChangedEventArgs)

Raises the CollectionChanged event with the provided arguments.

(Inherited from ObservableCollection<T>)
OnPropertyChanged(PropertyChangedEventArgs)

Raises the PropertyChanged event with the provided arguments.

(Inherited from ObservableCollection<T>)
Remove(T)

Removes the first occurrence of a specific object from the Collection<T>.

(Inherited from Collection<T>)
RemoveAt(Int32)

Removes the element at the specified index of the Collection<T>.

(Inherited from Collection<T>)
RemoveItem(Int32)

Removes the item at the specified index of the collection.

(Inherited from ObservableCollection<T>)
SetItem(Int32, T)

Replaces the element at the specified index.

(Inherited from ObservableCollection<T>)
ToString()

Returns a string that represents the current object.

(Inherited from Object)

Events

CollectionChanged

Occurs when an item is added, removed, changed, moved, or the entire list is refreshed.

(Inherited from ObservableCollection<T>)
PropertyChanged

Occurs when a property value changes.

(Inherited from ObservableCollection<T>)

Explicit Interface Implementations

ICollection.CopyTo(Array, Int32)

Copies the elements of the ICollection to an Array, starting at a particular Array index.

(Inherited from Collection<T>)
ICollection.IsSynchronized

Gets a value indicating whether access to the ICollection is synchronized (thread safe).

(Inherited from Collection<T>)
ICollection.SyncRoot

Gets an object that can be used to synchronize access to the ICollection.

(Inherited from Collection<T>)
ICollection<T>.IsReadOnly

Gets a value indicating whether the ICollection<T> is read-only.

(Inherited from Collection<T>)
IEnumerable.GetEnumerator()

Returns an enumerator that iterates through a collection.

(Inherited from Collection<T>)
IList.Add(Object)

Adds an item to the IList.

(Inherited from Collection<T>)
IList.Contains(Object)

Determines whether the IList contains a specific value.

(Inherited from Collection<T>)
IList.IndexOf(Object)

Determines the index of a specific item in the IList.

(Inherited from Collection<T>)
IList.Insert(Int32, Object)

Inserts an item into the IList at the specified index.

(Inherited from Collection<T>)
IList.IsFixedSize

Gets a value indicating whether the IList has a fixed size.

(Inherited from Collection<T>)
IList.IsReadOnly

Gets a value indicating whether the IList is read-only.

(Inherited from Collection<T>)
IList.Item[Int32]

Gets or sets the element at the specified index.

(Inherited from Collection<T>)
IList.Remove(Object)

Removes the first occurrence of a specific object from the IList.

(Inherited from Collection<T>)
INotifyPropertyChanged.PropertyChanged

Occurs when a property value changes.

(Inherited from ObservableCollection<T>)

Extension Methods

CopyToDataTable<T>(IEnumerable<T>)

Returns a DataTable that contains copies of the DataRow objects, given an input IEnumerable<T> object where the generic parameter T is DataRow.

CopyToDataTable<T>(IEnumerable<T>, DataTable, LoadOption)

Copies DataRow objects to the specified DataTable, given an input IEnumerable<T> object where the generic parameter T is DataRow.

CopyToDataTable<T>(IEnumerable<T>, DataTable, LoadOption, FillErrorEventHandler)

Copies DataRow objects to the specified DataTable, given an input IEnumerable<T> object where the generic parameter T is DataRow.

Cast<TResult>(IEnumerable)

Casts the elements of an IEnumerable to the specified type.

OfType<TResult>(IEnumerable)

Filters the elements of an IEnumerable based on a specified type.

AsParallel(IEnumerable)

Enables parallelization of a query.

AsQueryable(IEnumerable)

Converts an IEnumerable to an IQueryable.

Ancestors<T>(IEnumerable<T>)

Returns a collection of elements that contains the ancestors of every node in the source collection.

Ancestors<T>(IEnumerable<T>, XName)

Returns a filtered collection of elements that contains the ancestors of every node in the source collection. Only elements that have a matching XName are included in the collection.

DescendantNodes<T>(IEnumerable<T>)

Returns a collection of the descendant nodes of every document and element in the source collection.

Descendants<T>(IEnumerable<T>)

Returns a collection of elements that contains the descendant elements of every element and document in the source collection.

Descendants<T>(IEnumerable<T>, XName)

Returns a filtered collection of elements that contains the descendant elements of every element and document in the source collection. Only elements that have a matching XName are included in the collection.

Elements<T>(IEnumerable<T>)

Returns a collection of the child elements of every element and document in the source collection.

Elements<T>(IEnumerable<T>, XName)

Returns a filtered collection of the child elements of every element and document in the source collection. Only elements that have a matching XName are included in the collection.

InDocumentOrder<T>(IEnumerable<T>)

Returns a collection of nodes that contains all nodes in the source collection, sorted in document order.

Nodes<T>(IEnumerable<T>)

Returns a collection of the child nodes of every document and element in the source collection.

Remove<T>(IEnumerable<T>)

Removes every node in the source collection from its parent node.

Applies to

See also