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
        }
    }
};

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;
}

@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

I wanted to add a comment but I have less than 50 pts so I can only "Answer". Be aware that if you use the "VisualTreeHelper" method to retrieve XAML "TextBlock" objects then it will also grab XAML "Button" objects. If you re-initialize the "TextBlock" object by writing to the Textblock.Text parameter then you will no longer be able to change the Button text using the Button.Content parameter. The Button will permanently show the text written to it from the Textblock.Text write action (from when it was retrieved --

foreach (TextBlock tb in FindVisualChildren<TextBlock>(window))
{
// do something with tb here
   tb.Text = ""; //this will overwrite Button.Content and render the 
                 //Button.Content{set} permanently disabled.
}

要解决这个问题，您可以尝试使用XAML“文本框”并添加方法(或事件)来模拟XAMAL按钮。XAML“TextBox”不是通过搜索“TextBlock”收集的。

这应该可以达到目的:

public static IEnumerable<T> FindVisualChilds<T>(DependencyObject depObj) where T : DependencyObject
{
    if (depObj == null) yield return (T)Enumerable.Empty<T>();
    for (int i = 0; i < VisualTreeHelper.GetChildrenCount(depObj); i++)
    {
        DependencyObject ithChild = VisualTreeHelper.GetChild(depObj, i);
        if (ithChild == null) continue;
        if (ithChild is T t) yield return t;
        foreach (T childOfChild in FindVisualChilds<T>(ithChild)) yield return childOfChild;
    }
}

然后像这样枚举控件

foreach (TextBlock tb in FindVisualChildren<TextBlock>(window))
{
    // do something with tb here
}