private void help_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
        {
            if (_IsTopicPresent())
            {
                HelpTopics topics = App.Current.HelpTopics;
                HelpTopic topic = topics.GetTopic(AppPages.PagePaths.MainPage);
                Debug.Assert(null != topic);

                HelpLinkCommand cmd = new HelpLinkCommand(topic.Path, topic.Key);
                cmd.Execute(null);
            }
        }
        /// <summary>
        /// Initialize control with help text.
        /// </summary>
        private void _InitQuickHelpText()
        {
            HelpTopic topic = ((PageBase)this._Page).HelpTopic;
            if (null != topic)
            {
                QuickHelpText.Inlines.Clear();

                List<Inline> inlines = new List<Inline>();
                if (!string.IsNullOrEmpty(topic.QuickHelpText))
                    QuickHelpText.Inlines.Add(topic.QuickHelpText.Trim());

                if (!string.IsNullOrEmpty(topic.Key) || !string.IsNullOrEmpty(topic.Path))
                {
                    if (!string.IsNullOrEmpty(topic.QuickHelpText))
                        QuickHelpText.Inlines.Add(" ");

                    Hyperlink helpLink = new Hyperlink(new Run((string)App.Current.FindResource("QuickHelpLinkCaption")));
                    _command = new HelpLinkCommand(topic.Path, topic.Key);
                    helpLink.Command = _command;
                    QuickHelpText.Inlines.Add(helpLink);
                }
            }
        }