exciton80……我有一个问题，你的代码不递归通过用户控件。它击中了网格根并抛出了一个错误。我相信这能解决我的问题:

public static object[] FindControls(this FrameworkElement f, Type childType, int maxDepth)
{
    return RecursiveFindControls(f, childType, 1, maxDepth);
}

private static object[] RecursiveFindControls(object o, Type childType, int depth, int maxDepth = 0)
{
    List<object> list = new List<object>();
    var attrs = o.GetType().GetCustomAttributes(typeof(ContentPropertyAttribute), true);
    if (attrs != null && attrs.Length > 0)
    {
        string childrenProperty = (attrs[0] as ContentPropertyAttribute).Name;
        if (String.Equals(childrenProperty, "Content") || String.Equals(childrenProperty, "Children"))
        {
            var collection = o.GetType().GetProperty(childrenProperty).GetValue(o, null);
            if (collection is System.Windows.Controls.UIElementCollection) // snelson 6/6/11
            {
                foreach (var c in (IEnumerable)collection)
                {
                    if (c.GetType().FullName == childType.FullName)
                        list.Add(c);
                    if (maxDepth == 0 || depth < maxDepth)
                        list.AddRange(RecursiveFindControls(
                            c, childType, depth + 1, maxDepth));
                }
            }
            else if (collection != null && collection.GetType().BaseType.Name == "Panel") // snelson 6/6/11; added because was skipping control (e.g., System.Windows.Controls.Grid)
            {
                if (maxDepth == 0 || depth < maxDepth)
                    list.AddRange(RecursiveFindControls(
                        collection, childType, depth + 1, maxDepth));
            }
        }
    }
    return list.ToArray();
}

这里有一些我经常使用的方法。

用法:

// Starts the search from thisUiElement (might be a UserContol, Window, etc..)
var combobox = thisUiElement.ChildOfType<ComboBox>();
var employeesListBox = thisUiElement.ChildOfName("EmployeesListBox");
// Starts the search from MainWindow to find the first DataGrid
var dataGrid = WpfUtils.ChildOfType<DataGrid>();
// Starts the search from MainWindow to find the all ListViews
List<ComboBox> allListViews = WpfUtils.ChildOfType<ListView>();
// Starts the search from MainWindow to find the element of name EmployeesComboBox
var combobox = WpfUtils.ChildOfName("EmployeesComboBox");

实现:

/*
using System.Collections.Generic;
using System.Windows;
using System.Windows.Media;

namespace WpfUtilities;
*/

public static class WpfUtils{

    public static Window AppMainWindow =>
        Application.Current?.MainWindow;

    #region Find By Type
    
    // Start the search from MainWindow, example usage: var combobox = WpfUtils.ChildOfType<ComboBox>();
    public static T ChildOfType<T>() where T : DependencyObject =>
        ChildOfType<T>(AppMainWindow);
        
    /// This will return the first child of type T
    public static T ChildOfType<T>(this DependencyObject parent)
        where T : DependencyObject
    {
        if (parent == null) return null;
        T child = default;
        var numVisuals = VisualTreeHelper.GetChildrenCount(parent);
        for (var i = 0; i < numVisuals; i++)
        {
            var v = VisualTreeHelper.GetChild(parent, i);
            child = v as T ?? v.ChildOfType<T>();
            if (child != null)
                break;
        }

        return child;
    }
    
    // Start the search from MainWindow, example usage: List<ComboBox> comboboxes = WpfUtils.ChildOfType<ComboBox>();
    public static IEnumerable<T> ChildrenOfType<T>() where T : DependencyObject =>
        ChildrenOfType<T>(AppMainWindow);
    
    /// This will not break the search when finding the first kid of type T, but it will keep searching to return all kids of type T
    public static IEnumerable<T> ChildrenOfType<T>(
        this DependencyObject parent) where T : DependencyObject
    {
        if (parent == null) yield break;
        var numVisuals = VisualTreeHelper.GetChildrenCount(parent);
        for (var i = 0; i < numVisuals; i++)
        {
            var child = VisualTreeHelper.GetChild(parent, i);
            if (child is T dependencyObject)
                yield return dependencyObject;

            foreach (var childOfChild in child.ChildrenOfType<T>())
                yield return childOfChild;
        }
    }
    
    #endregion  

    #region Find By Name
    
    /// If parent is null, the search will start from MainWindow, example usage: var combobox = WpfUtils.ChildOfName("EmployeesCombobox");
    public static FrameworkElement ChildOfName(string childName,
        DependencyObject parent = null)
    {
        parent ??= AppMainWindow;
        object child = null;
        var numVisuals = VisualTreeHelper.GetChildrenCount(parent);
        for (var i = 0; i < numVisuals; i++)
        {
            var v = VisualTreeHelper.GetChild(parent, i);
            child = v is FrameworkElement f && f.Name == childName
                ? f
                : ChildOfName(childName, v);

            if (child != null)
                break;
        }

        return child as FrameworkElement;
    }
    
    #endregion
    
    #region
    
    // Yet another useful method, if you are writing code in a .xaml.cs file and you want to get the parent of a type.. example usage: this.ParentOfType<Grid>(); this.ParentOfType<UserControl>(); this.ParentOfType<Window>(); 
    public static T ParentOfType<T>(this DependencyObject child) where T : DependencyObject
    {
        var parentDepObj = child;
        do
        {
            parentDepObj = VisualTreeHelper.GetParent(parentDepObj);
            if (parentDepObj is T parent) return parent;
        } while (parentDepObj != null);

        return null;
    }
    
    #endregion
}

因为这个问题很普遍，它可能会吸引人们去寻找非常琐碎的情况的答案:如果你只想要一个孩子而不是后代，你可以使用Linq:

private void ItemsControlItem_Loaded(object sender, RoutedEventArgs e)
{
    if (SomeCondition())
    {
        var children = (sender as Panel).Children;
        var child = (from Control child in children
                 where child.Name == "NameTextBox"
                 select child).First();
        child.Focus();
    }
}

或者显然的for循环遍历Children。

我能够找到对象的名称使用下面的代码。

stkMultiChildControl = stkMulti.FindChild（“<StackPanel>stkMultiControl_” + couter.ToString（））;

我有一个这样的序列函数(这是完全一般的):

    public static IEnumerable<T> SelectAllRecursively<T>(this IEnumerable<T> items, Func<T, IEnumerable<T>> func)
    {
        return (items ?? Enumerable.Empty<T>()).SelectMany(o => new[] { o }.Concat(SelectAllRecursively(func(o), func)));
    }

有直系子女:

    public static IEnumerable<DependencyObject> FindChildren(this DependencyObject obj)
    {
        return Enumerable.Range(0, VisualTreeHelper.GetChildrenCount(obj))
            .Select(i => VisualTreeHelper.GetChild(obj, i));
    }

在树中找到所有的子节点:

    public static IEnumerable<DependencyObject> FindAllChildren(this DependencyObject obj)
    {
        return obj.FindChildren().SelectAllRecursively(o => o.FindChildren());
    }

你可以在Window上调用这个来获得所有的控件。

在你有集合之后，你可以使用LINQ(即OfType, Where)。

下面是一个使用灵活谓词的解决方案:

public static DependencyObject FindChild(DependencyObject parent, Func<DependencyObject, bool> predicate)
{
    if (parent == null) return null;

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

        if (predicate(child))
        {
            return child;
        }
        else
        {
            var foundChild = FindChild(child, predicate);
            if (foundChild != null)
                return foundChild;
        }
    }

    return null;
}

例如，你可以这样称呼它:

var child = FindChild(parent, child =>
{
    var textBlock = child as TextBlock;
    if (textBlock != null && textBlock.Name == "MyTextBlock")
        return true;
    else
        return false;
}) as TextBlock;