下面是我的代码，通过类型来查找控件，同时控制我们进入层次结构的深度 (maxDepth == 0表示无限深)。

public static class FrameworkElementExtension
{
    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;
            foreach (var c in (IEnumerable)o.GetType()
                .GetProperty(childrenProperty).GetValue(o, null))
            {
                if (c.GetType().FullName == childType.FullName)
                    list.Add(c);
                if (maxDepth == 0 || depth < maxDepth)
                    list.AddRange(RecursiveFindControls(
                        c, childType, depth + 1, maxDepth));
            }
        }
        return list.ToArray();
    }
}

我编辑了CrimsonX的代码，因为它不能处理超类类型:

public static T FindChild<T>(DependencyObject depObj, string childName)
   where T : DependencyObject
{
    // Confirm obj is valid. 
    if (depObj == null) return null;

    // success case
    if (depObj is T && ((FrameworkElement)depObj).Name == childName)
        return depObj as T;

    for (int i = 0; i < VisualTreeHelper.GetChildrenCount(depObj); i++)
    {
        DependencyObject child = VisualTreeHelper.GetChild(depObj, i);

        //DFS
        T obj = FindChild<T>(child, childName);

        if (obj != null)
            return obj;
    }

    return null;
}

我找不到@CrimsonX或@Drew Noakes方法的控件，因为我的ControlTemplate位于一个单独的XAML文件中。 我用下面的方法找到了控件:

private Image backImage;
private void Diagram_Loaded(object sender, System.Windows.RoutedEventArgs e)
{
    // here is the example of the ControlTemplate declaration
    //<ControlTemplate x:Key="DiagramControlTemplate1" TargetType="{x:Type Diagram}">
    var ctrlTemplate = (ControlTemplate)FindResource("DiagramControlTemplate1");
    // diagram is the x:Name of TemplatedControl and, "backImage" is the name of control that I want to find.
    var imageControl = ctrlTemplate.FindName("backImage", diagram);
    if (imageControl != null)
    {
        this.backImage = (Image)imageControl;
    }
}

这对我很有用。

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
}

如果您希望找到特定类型的ALL控件，那么您可能也会对这个代码段感兴趣

    public static IEnumerable<T> FindVisualChildren<T>(DependencyObject parent) 
        where T : DependencyObject
    {
        int childrenCount = VisualTreeHelper.GetChildrenCount(parent);
        for (int i = 0; i < childrenCount; i++)
        {
            var child = VisualTreeHelper.GetChild(parent, i);

            var childType = child as T;
            if (childType != null)
            {
                yield return (T)child;
            }

            foreach (var other in FindVisualChildren<T>(child))
            {
                yield return other;
            }
        }
    }

对代码的扩展。

增加了重载，以按类型、按类型和标准(谓词)查找一个子元素，查找符合标准的所有类型的子元素 FindChildren方法除了是DependencyObject的扩展方法外，还是一个迭代器 FindChildren还遍历逻辑子树。请参阅博客中链接的Josh Smith的文章。

来源: https://code.google.com/p/gishu-util/source/browse/#git%2FWPF%2FUtilities

解释性博客文章: http://madcoderspeak.blogspot.com/2010/04/wpf-find-child-control-of-specific-type.html