WPF: Find All Child Controls Of A Type

The following DependencyObject extension method (compatible with both WPF and Silverlight) recursively traverses the visual tree searching for children of the type specified by type parameter TChild before returning a collection containing the matches.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Media;


namespace WPFFindAllChildren
{
    public static class DependencyObjectExtension
    {
        public static List<TChild> FindChildren<TChild>(this DependencyObject d)
            where TChild : DependencyObject
        {
            List<TChild> children = new List<TChild>();

            int childCount = VisualTreeHelper.GetChildrenCount(d);

            for (int i = 0; i < childCount; i++)
            {
                DependencyObject o = VisualTreeHelper.GetChild(d, i);

                if (o is TChild)
                    children.Add(o as TChild);

                foreach (TChild c in o.FindChildren<TChild>())
                    children.Add(c);
            }

            return children;
        }
    }
}

Usage

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;

namespace WPFFindAllChildren
{
    public partial class Window1 : Window
    {
        public Window1()
        {
            InitializeComponent();            
        }

        void Window1_Loaded(object sender, RoutedEventArgs e)
        {
            StackPanel stack1 = new StackPanel();
            stack1.Children.Add(new CheckBox());
            stack1.Children.Add(new CheckBox());

            StackPanel stack2 = new StackPanel();
            stack2.Children.Add(new CheckBox());
            stack2.Children.Add(stack1);

            LayoutRoot.Children.Add(stack2);

            this.FindChildren<CheckBox>().ForEach(x => x.IsChecked = true);
        }
    }
}

Download Sample