How to: Create and Bind to an ObservableCollection

This example shows how to create and bind to a collection that derives from the ObservableCollection<T> class, which is a collection class that provides notifications when items get added or removed.

Example

The following example shows the implementation of a NameList collection:

public class NameList : ObservableCollection<PersonName>
{
 public NameList() : base()
 {
 Add(new PersonName("Willa", "Cather"));
 Add(new PersonName("Isak", "Dinesen"));
 Add(new PersonName("Victor", "Hugo"));
 Add(new PersonName("Jules", "Verne"));
 }
 }

 public class PersonName
 {
 private string firstName;
 private string lastName;

 public PersonName(string first, string last)
 {
 this.firstName = first;
 this.lastName = last;
 }

 public string FirstName
 {
 get { return firstName; }
 set { firstName = value; }
 }

 public string LastName
 {
 get { return lastName; }
 set { lastName = value; }
 }
 }

Public Class NameList
 Inherits ObservableCollection(Of PersonName)

 ' Methods
 Public Sub New()
 MyBase.Add(New PersonName("Willa", "Cather"))
 MyBase.Add(New PersonName("Isak", "Dinesen"))
 MyBase.Add(New PersonName("Victor", "Hugo"))
 MyBase.Add(New PersonName("Jules", "Verne"))
 End Sub

End Class

Public Class PersonName
 ' Methods
 Public Sub New(ByVal first As String, ByVal last As String)
 Me._firstName = first
 Me._lastName = last
 End Sub

 ' Properties
 Public Property FirstName() As String
 Get
 Return Me._firstName
 End Get
 Set(ByVal value As String)
 Me._firstName = value
 End Set
 End Property

 Public Property LastName() As String
 Get
 Return Me._lastName
 End Get
 Set(ByVal value As String)
 Me._lastName = value
 End Set
 End Property

 ' Fields
 Private _firstName As String
 Private _lastName As String
End Class

You can make the collection available for binding the same way you would with other common language runtime (CLR) objects, as described in Make Data Available for Binding in XAML. For example, you can instantiate the collection in XAML and specify the collection as a resource, as shown here:

<Window
 xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
 xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
 xmlns:c="clr-namespace:SDKSample"
 x:Class="SDKSample.Window1"
 Width="400"
 Height="280"
 Title="MultiBinding Sample">

 <Window.Resources>
 <c:NameList x:Key="NameListData"/>

...

</Window.Resources>

You can then bind to the collection:

<ListBox Width="200"
 ItemsSource="{Binding Source={StaticResource NameListData}}"
 ItemTemplate="{StaticResource NameItemTemplate}"
 IsSynchronizedWithCurrentItem="True"/>

The definition of NameItemTemplate is not shown here.

For more information, see the Binding to Collections section in the Data Binding Overview.

See also

• Sort Data in a View
• Filter Data in a View
• Sort and Group Data Using a View in XAML
• Data Binding Overview
• How-to Topics