AnotherReplayReader/Utils/WpfExtensions.cs

using System.Collections.Generic;
using System.Windows;

namespace AnotherReplayReader.Utils
{
    internal static class WpfExtensions
    {
        public static IEnumerable<T> FindVisualChildren<T>(this DependencyObject depObj) where T : DependencyObject
        {
            foreach (var x in LogicalTreeHelper.GetChildren(depObj))
            {
                if (x is not DependencyObject child)
                {
                    continue;
                }

                if (child is T tchild)
                {
                    yield return tchild;
                }

                foreach (var childOfChild in FindVisualChildren<T>(child))
                {
                    yield return childOfChild;
                }
            }
        }
    }
}