Integrated Help System in a WPF Application

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Media;
using Microsoft.Win32;

namespace IntegratedHelpInWPF
{
    public static class Utility
    {
        public static DependencyObject GetParentObject(this DependencyObject child)
        {
            if (child == null) return null;

            //handle content elements separately
            var contentElement = child as ContentElement;
            if (contentElement != null)
            {
                DependencyObject parent = ContentOperations.GetParent(contentElement);
                if (parent != null) return parent;

                var fce = contentElement as FrameworkContentElement;
                return fce != null ? fce.Parent : null;
            }

            //also try searching for parent in framework elements (such as DockPanel, etc)
            var frameworkElement = child as FrameworkElement;
            if (frameworkElement != null)
            {
                DependencyObject parent = frameworkElement.Parent;
                if (parent != null) return parent;
            }

            //if it's not a ContentElement/FrameworkElement, rely on VisualTreeHelper
            return VisualTreeHelper.GetParent(child);
        }

        public static bool CheckParent(this DependencyObject child, DependencyObject parentToCheck)
        {
            if (child.Equals(parentToCheck))
                return true;
            //get parent item
            DependencyObject parentObject = GetParentObject(child);

            //we've reached the end of the tree
            if (parentObject == null)
                return false;
            //use recursion to proceed with next level
            return CheckParent(parentObject, parentToCheck);
        }

        /// <summary>
        /// method for retrieving the users default web browser
        /// </summary>
        /// <returns></returns>
        public static string GetSystemDefaultBrowser()
        {
            string name = string.Empty;
            RegistryKey regKey = null;

            try
            {
                //set the registry key we want to open
                regKey = Registry.ClassesRoot.OpenSubKey(@"HTTP\shell\open\command", false);

                //get rid of the enclosing quotes
                name = regKey.GetValue(null).ToString().ToLower().Replace("" + (char)34, "");

                //check to see if the value ends with .exe (this way we can remove any command line arguments)
                if (!name.EndsWith("exe"))
                    //get rid of all command line arguments (anything after the .exe must go)
                    name = name.Substring(0, name.LastIndexOf(".exe") + 4);

            }
            finally
            {
                //check and see if the key is still open, if so
                //then close it
                if (regKey != null)
                    regKey.Close();
            }
            //return the value
            return name;
        }
    }


}