断开元素与 WPF 中任何/未指定的父容器的连接

您可以使用扩展方法编写一个帮助程序类：

public static class RemoveChildHelper
{
    public static void RemoveChild(this DependencyObject parent, UIElement child)
    {
        var panel = parent as Panel;
        if (panel != null)
        {
            panel.Children.Remove(child);
            return;
        }
        var decorator = parent as Decorator;
        if (decorator != null)
        {
            if (decorator.Child == child)
            {
                decorator.Child = null;
            }
            return;
        }
        var contentPresenter = parent as ContentPresenter;
        if (contentPresenter != null)
        {
            if (contentPresenter.Content == child)
            {
                contentPresenter.Content = null;
            }
            return;
        }
        var contentControl = parent as ContentControl;
        if (contentControl != null)
        {
            if (contentControl.Content == child)
            {
                contentControl.Content = null;
            }
            return;
        }
        // maybe more
    }
}

新增：

我建议使用基类而不是列出的所有其他类。试试这段代码，这 3 个类是满足您需求的大多数用例。据我了解，它与 previos 几乎相同^）

  var parent = VisualTreeHelper.GetParent(child);
  var parentAsPanel = parent as Panel;
  if (parentAsPanel != null)
  {
      parentAsPanel.Children.Remove(child);
  }
  var parentAsContentControl = parent as ContentControl;
  if (parentAsContentControl != null)
  {
      parentAsContentControl.Content = null;
  }
  var parentAsDecorator = parent as Decorator;
  if (parentAsDecorator != null)
  {
      parentAsDecorator.Child = null;
  }

老：据我所知，您可以使用视觉类型作为父类型并尝试调用RemoveVisualChild方法。

为了完整起见，我添加了 ItemsControl 检查，以及一个 Add 方法，该方法将把孩子放回原处。 子项或父项可能尚未在可视化树中，因此您必须同时检查可视化树和逻辑树：

    /// <summary>
    /// Adds or inserts a child back into its parent
    /// </summary>
    /// <param name="child"></param>
    /// <param name="index"></param>
    public static void AddToParent(this UIElement child, DependencyObject parent, int? index = null)
    {
        if (parent == null)
            return;
        if (parent is ItemsControl itemsControl)
            if (index == null)
                itemsControl.Items.Add(child);
            else
                itemsControl.Items.Insert(index.Value, child);
        else if (parent is Panel panel)
            if (index == null)
                panel.Children.Add(child);
            else
                panel.Children.Insert(index.Value, child);
        else if (parent is Decorator decorator)
            decorator.Child = child;
        else if (parent is ContentPresenter contentPresenter)
            contentPresenter.Content = child;
        else if (parent is ContentControl contentControl)
            contentControl.Content = child;
    }
    /// <summary>
    /// Removes the child from its parent collection or its content.
    /// </summary>
    /// <param name="child"></param>
    /// <param name="parent"></param>
    /// <returns></returns>
    public static bool RemoveFromParent(this UIElement child, out DependencyObject parent, out int? index)
    {
        parent = child.GetParent(true);
        if (parent == null)
            parent = child.GetParent(false);
        index = null;
        if (parent == null)
            return false;
        if (parent is ItemsControl itemsControl)
        {
            if (itemsControl.Items.Contains(child))
            {
                index = itemsControl.Items.IndexOf(child);
                itemsControl.Items.Remove(child);
                return true;
            }
        }
        else if (parent is Panel panel)
        {
            if (panel.Children.Contains(child))
            {
                index = panel.Children.IndexOf(child);
                panel.Children.Remove(child);
                return true;
            }
        }
        else if (parent is Decorator decorator)
        {
            if (decorator.Child == child)
            {
                decorator.Child = null;
                return true;
            }
        }
        else if (parent is ContentPresenter contentPresenter)
        {
            if (contentPresenter.Content == child)
            {
                contentPresenter.Content = null;
                return true;
            }
        }
        else if (parent is ContentControl contentControl)
        {
            if (contentControl.Content == child)
            {
                contentControl.Content = null;
                return true;
            }
        }
        return false;
    }
    public static DependencyObject GetParent(this DependencyObject depObj, bool isVisualTree)
    {
        if (isVisualTree)
        {
            if(depObj is Visual || depObj is Visual3D)
                return VisualTreeHelper.GetParent(depObj);
            return null;
        }
        else
            return LogicalTreeHelper.GetParent(depObj);
    }

我的@Clemens解决方案版本：

    /// <summary>
    /// Disconnects <paramref name="child"/> from it's parent if any.
    /// </summary>
    /// <param name="child"></param>
    public static void DisconnectIt(this FrameworkElement child)
    {
        var parent = child.Parent;
        if (parent == null)
            return;
        if (parent is Panel panel)
        {
            panel.Children.Remove(child);
            return;
        }
        if (parent is Decorator decorator)
        {
            if (decorator.Child == child)
                decorator.Child = null;
            return;
        }
        if (parent is ContentPresenter contentPresenter)
        {
            if (contentPresenter.Content == child)
                contentPresenter.Content = null;
            return;
        }
        if (parent is ContentControl contentControl)
        {
            if (contentControl.Content == child)
                contentControl.Content = null;
            return;
        }
        //if (parent is ItemsControl itemsControl)
        //{
        //  itemsControl.Items.Remove(child);
        //  return;
        //}
    }