找到视觉树的方法

private T FindVisualChild<T>(DependencyObject obj) where T : DependencyObject
        {
            for (int i = 0; i < VisualTreeHelper.GetChildrenCount(obj); i++)
            {
                DependencyObject child = VisualTreeHelper.GetChild(obj, i);
                if (child != null && child is T)
                {
                    return (T)child;
                }
                var childOfChild = FindVisualChild<T>(child);
                if (childOfChild != null)
                {
                    return childOfChild;
                }
            }
            return null;
        }



public static T FindVisualParent<T>(DependencyObject child) where T : DependencyObject
        {
            DependencyObject dependencyObject = VisualTreeHelper.GetParent(child);
            if (dependencyObject != null)
            {
                T parent = dependencyObject as T;
                if (parent != null)
                {
                    return parent;
                }
                else
                {
                    return FindVisualParent<T>(dependencyObject);
                }
            }
            else
            {
                return null;
            }
        }