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:

C#

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; }  
      }  
  }  

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:

XAML

<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:

XAML

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

The definition of NameItemTemplate is not shown here.

Note

The objects in your collection must satisfy the requirements described in the Binding Sources Overview. In particular, if you are using OneWay or TwoWay (for example, you want your UI to update when the source properties change dynamically), you must implement a suitable property changed notification mechanism such as the INotifyPropertyChanged interface.

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