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

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;
}

虽然我一般喜欢递归，但在c#中编程时，它不如迭代有效，所以也许下面的解决方案比John Myczek建议的更整洁?这将从给定控件搜索层次结构，以查找特定类型的祖先控件。

public static T FindVisualAncestorOfType<T>(this DependencyObject Elt)
    where T : DependencyObject
{
    for (DependencyObject parent = VisualTreeHelper.GetParent(Elt);
        parent != null; parent = VisualTreeHelper.GetParent(parent))
    {
        T result = parent as T;
        if (result != null)
            return result;
    }
    return null;
}

像这样调用它来找到包含一个名为ExampleTextBox的控件的窗口:

Window window = ExampleTextBox.FindVisualAncestorOfType<Window>();

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。

这段代码只是修复了@CrimsonX回答的错误:

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

      T foundChild = null;

      int childrenCount = VisualTreeHelper.GetChildrenCount(parent);
      for (int i = 0; i < childrenCount; i++)
      {
        var child = VisualTreeHelper.GetChild(parent, i);
        // If the child is not of the request child type child
        T childType = child as T;
        if (childType == null)
        {
          // recursively drill down the tree
          foundChild = FindChild<T>(child, childName);

          // If the child is found, break so we do not overwrite the found child. 
          if (foundChild != null) break;
        }
        else if (!string.IsNullOrEmpty(childName))
        {
          var frameworkElement = child as FrameworkElement;
          // If the child's name is set for search
          if (frameworkElement != null && frameworkElement.Name == childName)
          {
            // if the child's name is of the request name
            foundChild = (T)child;
            break;
          }

 // recursively drill down the tree
          foundChild = FindChild<T>(child, childName);

          // If the child is found, break so we do not overwrite the found child. 
          if (foundChild != null) break;


        else
        {
          // child element found.
          foundChild = (T)child;
          break;
        }
      }

      return foundChild;
    }  

你只需要继续递归调用方法，如果类型匹配，但名称不匹配(这发生在你传递FrameworkElement作为T时)，否则它将返回null，这是错误的。

我可能只是在重复其他人，但我确实有一段漂亮的代码，它用FindChild()方法扩展了DependencyObject类，该方法将按类型和名称获取子对象。只是包含和使用。

public static class UIChildFinder
{
    public static DependencyObject FindChild(this DependencyObject reference, string childName, Type childType)
    {
        DependencyObject foundChild = null;
        if (reference != null)
        {
            int childrenCount = VisualTreeHelper.GetChildrenCount(reference);
            for (int i = 0; i < childrenCount; i++)
            {
                var child = VisualTreeHelper.GetChild(reference, i);
                // If the child is not of the request child type child
                if (child.GetType() != childType)
                {
                    // recursively drill down the tree
                    foundChild = FindChild(child, childName, childType);
                    if (foundChild != null) break;
                }
                else if (!string.IsNullOrEmpty(childName))
                {
                    var frameworkElement = child as FrameworkElement;
                    // If the child's name is set for search
                    if (frameworkElement != null && frameworkElement.Name == childName)
                    {
                        // if the child's name is of the request name
                        foundChild = child;
                        break;
                    }
                }
                else
                {
                    // child element found.
                    foundChild = child;
                    break;
                }
            }
        }
        return foundChild;
    }
}

希望对你有用。