Filter Data in a Collection, Set the Filter property to a FilterEventHandler


   
  

<Window x:Class="WpfApplication1.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="clr-namespace:WpfApplication1"
    Title="WPF" Height="124" Width="124">
    <Window.Resources>
        <local:Countries x:Key="countries"/>
        <CollectionViewSource x:Key="cvs" Source="{Binding Source={StaticResource countries}}"
            Filter="CollectionViewSource_EuropeFilter" />
    </Window.Resources>
    <Grid>

        <ItemsControl ItemsSource="{Binding Source={StaticResource cvs}}"
            DisplayMemberPath="Name"/>
    </Grid>

</Window>
//File:Window.xaml.cs
using System.Windows;
using System.Windows.Data;
using System.Collections.ObjectModel;

namespace WpfApplication1
{
    public partial class Window1 : Window
    {
        public Window1()
        {
            InitializeComponent();
        }
        private void CollectionViewSource_EuropeFilter(object sender, FilterEventArgs e)
        {
            Country country = e.Item as Country;
            e.Accepted = (country.Continent == Continent.Europe);
        }
    }

    public class Country
    {
        private string name;
        private Continent continent;

        public string Name
        {
            get{ return name;}
            set{name = value;}
        }

        public Continent Continent
        {
            get{return continent;}
            set{continent = value;}
        }

        public Country(string name, Continent continent)
        {
            this.name = name;
            this.continent = continent;
        }
    }

    public enum Continent
    {
        Europe,
        NorthAmerica,
    }

    public class Countries : Collection<Country>
    {
        public Countries()
        {
            this.Add(new Country("Great Britan", Continent.Europe));
            this.Add(new Country("USA", Continent.NorthAmerica));
            this.Add(new Country("Canada", Continent.NorthAmerica));
        }
    }
}