接受的答案返回发现的元素或多或少是无序的，方法是尽可能深入地跟随第一个子分支，同时在返回和重复尚未解析的树枝的步骤之前，沿途生成发现的元素。

如果你需要按降序排列的后代元素，其中直接的子元素将首先产生，然后是它们的子元素，依此类推，下面的算法将工作:

public static IEnumerable<T> GetVisualDescendants<T>(DependencyObject parent, bool applyTemplates = false)
    where T : DependencyObject
{
    if (parent == null || !(child is Visual || child is Visual3D))
        yield break;

    var descendants = new Queue<DependencyObject>();
    descendants.Enqueue(parent);

    while (descendants.Count > 0)
    {
        var currentDescendant = descendants.Dequeue();

        if (applyTemplates)
            (currentDescendant as FrameworkElement)?.ApplyTemplate();

        for (var i = 0; i < VisualTreeHelper.GetChildrenCount(currentDescendant); i++)
        {
            var child = VisualTreeHelper.GetChild(currentDescendant, i);

            if (child is Visual || child is Visual3D)
                descendants.Enqueue(child);

            if (child is T foundObject)
                yield return foundObject;
        }
    }
}

生成的元素将从最近到最远进行排序。 这将是有用的，例如，如果你正在寻找某种类型和条件的最近的子元素:

var foundElement = GetDescendants<StackPanel>(someElement)
                       .FirstOrDefault(o => o.SomeProperty == SomeState);

@Bryce，回答得很好。

VB。净版:

Public Shared Iterator Function FindVisualChildren(Of T As DependencyObject)(depObj As DependencyObject) As IEnumerable(Of T)
    If depObj IsNot Nothing Then
        For i As Integer = 0 To VisualTreeHelper.GetChildrenCount(depObj) - 1
            Dim child As DependencyObject = VisualTreeHelper.GetChild(depObj, i)
            If child IsNot Nothing AndAlso TypeOf child Is T Then
                Yield DirectCast(child, T)
            End If
            For Each childOfChild As T In FindVisualChildren(Of T)(child)
                Yield childOfChild
            Next
        Next
    End If
End Function

用法(这将禁用窗口中的所有文本框):

        For Each tb As TextBox In FindVisualChildren(Of TextBox)(Me)
          tb.IsEnabled = False
        Next

出于某种原因，这里发布的答案都没有帮助我在主窗口中获得给定控件中包含的给定类型的所有控件。 我需要在一个菜单中找到所有的菜单项来迭代它们。它们并不都是菜单的直接后代，所以我使用上面的任何代码只收集了它们的第一行。 这个扩展方法是我对这个问题的解决方案，任何人都将继续读到这里。

public static void FindVisualChildren<T>(this ICollection<T> children, DependencyObject depObj) where T : DependencyObject
    {
        if (depObj != null)
        {
            var brethren = LogicalTreeHelper.GetChildren(depObj);
            var brethrenOfType = LogicalTreeHelper.GetChildren(depObj).OfType<T>();
            foreach (var childOfType in brethrenOfType)
            {
                children.Add(childOfType);
            }

            foreach (var rawChild in brethren)
            {
                if (rawChild is DependencyObject)
                {
                    var child = rawChild as DependencyObject;
                    FindVisualChildren<T>(children, child);
                }
            }
        }
    }

希望能有所帮助。

这就是它向上的工作原理

    private T FindParent<T>(DependencyObject item, Type StopAt) where T : class
    {
        if (item is T)
        {
            return item as T;
        }
        else
        {
            DependencyObject _parent = VisualTreeHelper.GetParent(item);
            if (_parent == null)
            {
                return default(T);
            }
            else
            {
                Type _type = _parent.GetType();
                if (StopAt != null)
                {
                    if ((_type.IsSubclassOf(StopAt) == true) || (_type == StopAt))
                    {
                        return null;
                    }
                }

                if ((_type.IsSubclassOf(typeof(T)) == true) || (_type == typeof(T)))
                {
                    return _parent as T;
                }
                else
                {
                    return FindParent<T>(_parent, StopAt);
                }
            }
        }
    }

使用帮助类VisualTreeHelper或LogicalTreeHelper，这取决于你对哪棵树感兴趣。它们都提供了获取元素的子元素的方法(尽管语法略有不同)。我经常使用这些类来查找特定类型的第一个出现，但你可以很容易地修改它来查找该类型的所有对象:

public static DependencyObject FindInVisualTreeDown(DependencyObject obj, Type type)
{
    if (obj != null)
    {
        if (obj.GetType() == type)
        {
            return obj;
        }

        for (int i = 0; i < VisualTreeHelper.GetChildrenCount(obj); i++)
        {
            DependencyObject childReturn = FindInVisualTreeDown(VisualTreeHelper.GetChild(obj, i), type);
            if (childReturn != null)
            {
                return childReturn;
            }
        }
    }

    return null;
}

对于这个和更多的用例，你可以添加流动扩展方法到你的库:

 public static List<DependencyObject> FindAllChildren(this DependencyObject dpo, Predicate<DependencyObject> predicate)
    {
        var results = new List<DependencyObject>();
        if (predicate == null)
            return results;


        for (int i = 0; i < VisualTreeHelper.GetChildrenCount(dpo); i++)
        {
            var child = VisualTreeHelper.GetChild(dpo, i);
            if (predicate(child))
                results.Add(child);

            var subChildren = child.FindAllChildren(predicate);
            results.AddRange(subChildren);
        }
        return results;
    }

举个例子:

 var children = dpObject.FindAllChildren(child => child is TextBox);