How to get all controls/uielements in a window/page

Question

i want to get all Controls/UIElements in a window/page. how can i do this? i used this code but is not working and only return one element

private IEnumerable<UIElement> GetUI(UIElement root)
        {
            yield return root;
            if (root is Panel panel)
            {
                foreach (var item in panel.Children)
                {
                    GetUI(item);
                    yield return item;
                }
            }
        }

Answer 1

use this way:

var childs = grid.FindChildren();

extensions

 public static IEnumerable<FrameworkElement> FindChildren(this FrameworkElement element)
        {
        Start:

            if (element is Panel panel)
            {
                foreach (UIElement child in panel.Children)
                {
                    if (child is not FrameworkElement current)
                    {
                        continue;
                    }

                    yield return current;

                    foreach (FrameworkElement childOfChild in FindChildren(current))
                    {
                        yield return childOfChild;
                    }
                }
            }
            else if (element is ItemsControl itemsControl)
            {
                foreach (object item in itemsControl.Items)
                {
                    if (item is not FrameworkElement current)
                    {
                        continue;
                    }

                    yield return current;

                    foreach (FrameworkElement childOfChild in FindChildren(current))
                    {
                        yield return childOfChild;
                    }
                }
            }
            else if (element is ContentControl contentControl)
            {
                if (contentControl.Content is FrameworkElement content)
                {
                    yield return content;

                    element = content;

                    goto Start;
                }
            }
            else if (element is Border border)
            {
                if (border.Child is FrameworkElement child)
                {
                    yield return child;

                    element = child;

                    goto Start;
                }
            }
            else if (element is ContentPresenter contentPresenter)
            {
                if (contentPresenter.Content is FrameworkElement content)
                {
                    yield return content;

                    element = content;

                    goto Start;
                }
            }
            else if (element is Viewbox viewbox)
            {
                if (viewbox.Child is FrameworkElement child)
                {
                    yield return child;

                    element = child;

                    goto Start;
                }
            }
            else if (element is UserControl userControl)
            {
                if (userControl.Content is FrameworkElement content)
                {
                    yield return content;

                    element = content;

                    goto Start;
                }
            }
            else if (element.GetContentControl() is FrameworkElement containedControl)
            {
                yield return containedControl;

                element = containedControl;

                goto Start;
            }
        }
        public static UIElement? GetContentControl(this FrameworkElement element)
        {
            Type type = element.GetType();
            TypeInfo? typeInfo = type.GetTypeInfo();

            while (typeInfo is not null)
            {
                // We need to manually explore the custom attributes this way as the target one
                // is not returned by any of the other available GetCustomAttribute<T> APIs.
                foreach (CustomAttributeData attribute in typeInfo.CustomAttributes)
                {
                    if (attribute.AttributeType == typeof(ContentPropertyAttribute))
                    {
                        string propertyName = (string)attribute.NamedArguments[0].TypedValue.Value;
                        PropertyInfo? propertyInfo = type.GetProperty(propertyName);

                        return propertyInfo?.GetValue(element) as UIElement;
                    }
                }

                typeInfo = typeInfo.BaseType?.GetTypeInfo();
            }

            return null;
        }

Answer 2

Use the Visual Tree helper class from Microsoft

They even give you an example on how to use it

internal static void FindChildren<T>(List<T> results, DependencyObject startNode)
  where T : DependencyObject
{
    int count = VisualTreeHelper.GetChildrenCount(startNode);
    for (int i = 0; i < count; i++)
    {
        DependencyObject current = VisualTreeHelper.GetChild(startNode, i);
        if ((current.GetType()).Equals(typeof(T)) || (current.GetType().GetTypeInfo().IsSubclassOf(typeof(T))))
        {
            T asType = (T)current;
            results.Add(asType);
        }
        FindChildren<T>(results, current);
    }
}