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);

请注意，使用VisualTreeHelper仅适用于派生自Visual或Visual3D的控件。如果你还需要检查其他元素(例如TextBlock, FlowDocument等)，使用VisualTreeHelper将抛出一个异常。

如果有必要，这里有一个回到逻辑树的替代方案:

http://www.hardcodet.net/2009/06/finding-elements-in-wpf-tree-both-ways

@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

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);
                }
            }
        }
    }

我发现没有Visual Tree Helpers更容易:

foreach (UIElement element in MainWindow.Children) {
    if (element is TextBox) { 
        if ((element as TextBox).Text != "")
        {
            //Do something
        }
    }
};

下面是另一个紧凑的版本，使用泛型语法:

    public static IEnumerable<T> FindLogicalChildren<T>(DependencyObject obj) where T : DependencyObject
    {
        if (obj != null) {
            if (obj is T)
                yield return obj as T;

            foreach (DependencyObject child in LogicalTreeHelper.GetChildren(obj).OfType<DependencyObject>()) 
                foreach (T c in FindLogicalChildren<T>(child)) 
                    yield return c;
        }
    }