internal static void CacheRenderedTag(string virtualPath, IHtmlString renderedTag)
        {
            RenderedTags[virtualPath] = renderedTag;

            var ctx = HttpContext.Current;
            var physicalPath = ctx.Server.MapPath(virtualPath);
            if (File.Exists(physicalPath))
            {
                // add file watcher
                var fsw = new FileSystemWatcher(
                    Path.GetDirectoryName(physicalPath), Path.GetFileName(physicalPath));
                FileSystemWatchers.Add(fsw);

                // remove from lookup on change, to allow for creation of new md5 hash
                fsw.Renamed += (sender, args) =>
                {
                    RenderedTags.Remove(virtualPath);
                };
                fsw.Changed += (sender, args) =>
                {
                    RenderedTags.Remove(virtualPath);
                };
                fsw.Deleted += (sender, args) =>
                {
                    RenderedTags.Remove(virtualPath);
                };
                fsw.Created += (sender, args) =>
                {
                    RenderedTags.Remove(virtualPath);
                };

                fsw.EnableRaisingEvents = true;
            }
        }

    /// <summary>
    /// Inserts the given attributes at the end of all opening tags in this HtmlString.
    /// </summary>
    /// <param name="htmlString">The HTML string.</param>
    /// <param name="attributeValues">The attribute values.</param>
    /// <exception cref="System.NullReferenceException"></exception>
    /// <exception cref="System.ArgumentException">No opening tag in IHtmlString: {0} + html;htmlString</exception>
    private static IHtmlString InsertAttributes(IHtmlString htmlString, IEnumerable<Tuple<string, object>> attributeValues)
    {
        if (htmlString == null) throw new NullReferenceException();

        var attributes = new StringBuilder();
        foreach (var t in attributeValues)
        {
            attributes.AppendFormat(" {0}=\"{1}\"",
                HttpUtility.HtmlEncode(t.Item1).ToLower(),
                HttpUtility.HtmlEncode((t.Item2 ?? String.Empty).ToString()));
        }

        var html = htmlString.ToHtmlString();

        var matches = GetOpeningTagMatches(html);
        if (matches.Count == 0)
            throw new ArgumentException("No opening tag in IHtmlString: {0}" + html, "htmlString");

        foreach (Match match in matches)
        {
            var endOfOpeningTag = match.Groups[3].Index;
            html = html.Insert(endOfOpeningTag, attributes.ToString());
        }

        return new HtmlString(html);
    }

 protected bool HasTag(IHtmlString html, string tag)
 {
     var doc = new HtmlDocument();
     doc.LoadHtml(html.ToHtmlString());
     var xpath = "//" + tag;
     return doc.DocumentNode.SelectSingleNode(xpath) != null;
 }

 public static IHtmlString Concact(this IHtmlString html, IHtmlString other)
 {
     StringBuilder sb = new StringBuilder();
     sb.Append(html.ToString());
     sb.Append(other.ToString());
     return new HtmlString(sb.ToString());
 }

        public FlowFormField(TextWriter writer, bool containsSection, string labelHtml, string elementHtml, string errorHtml = "", bool isValid = true, IHtmlString hint = null, string tip = null, bool hideTip = true, string hintClass = null, string parentClass = null, bool displayFieldName = true)
        {
            _containsSection = containsSection;
            _writer = writer;

            var generatedSection = HelperDefinitions.BeginField(containsSection, displayFieldName ? new HtmlString(labelHtml) : null, new HtmlString(elementHtml), new HtmlString(errorHtml), isValid, hint, tip, hideTip, hintClass, parentClass);
            _writer.Write(generatedSection.ToHtmlString());
        }

 public static object Truncate(IHtmlString htmlString, int length)
 {
     if (htmlString.ToHtmlString().Length <= length)
     {
         return htmlString.ToHtmlString();
     }
     return htmlString.ToHtmlString().Substring(0, length) + "...";
 }

 public LabelAndControl(ViewContext viewContext, string labelFor, string labelText, IHtmlString control)
 {
     _labelFor = labelFor;
     _labelText = labelText;
     _control = control;
     _formLayout = viewContext.TempData["BootstrapFormLayout"].ToString();
     HtmlAttributes["class"] = "control-group";
 }

        public static IHtmlString CreateField(this HtmlHelper html, string title, IHtmlString input, IHtmlString validation = null)
        {
            var result = string.Format(@"<div class=""control-group""><label for=""control-label"">{0}</label><div class=""controls"">{1}</div></div>", title, input);
            if (validation != null) {
                result = string.Format(@"<div class=""control-group""><label for=""control-label"">{0}</label><div class=""controls"">{1}<p>{2}</p></div></div>", title, input, validation);
            }

            return new HtmlString(result);
        }

public static System.Web.WebPages.HelperResult BeginSection(IHtmlString title, IHtmlString leadingHtml, HtmlAttributes htmlAttributes) {
#line default
#line hidden
return new System.Web.WebPages.HelperResult(__razor_helper_writer => {

#line 14 "..\..\Templates\HtmlHelpers.cshtml"
                                                                                                 


#line default
#line hidden
WriteLiteralTo(__razor_helper_writer, "    <fieldset");


#line 15 "..\..\Templates\HtmlHelpers.cshtml"
WriteTo(__razor_helper_writer, htmlAttributes);


#line default
#line hidden
WriteLiteralTo(__razor_helper_writer, ">\r\n");

WriteLiteralTo(__razor_helper_writer, "        <legend>");


#line 16 "..\..\Templates\HtmlHelpers.cshtml"
WriteTo(__razor_helper_writer, title);


#line default
#line hidden
WriteLiteralTo(__razor_helper_writer, "</legend>\r\n");

WriteLiteralTo(__razor_helper_writer, "        ");


#line 17 "..\..\Templates\HtmlHelpers.cshtml"
WriteTo(__razor_helper_writer, leadingHtml);


#line default
#line hidden
WriteLiteralTo(__razor_helper_writer, "\r\n");

WriteLiteralTo(__razor_helper_writer, "        <dl>\r\n");


#line 19 "..\..\Templates\HtmlHelpers.cshtml"


#line default
#line hidden
});

#line 19 "..\..\Templates\HtmlHelpers.cshtml"
}

 public static MvcHtmlString ActionLink(this HtmlHelper htmlHelper,
                                        IHtmlString linkText,
                                        string actionName,
                                        string controllerName,
                                        RouteValueDictionary routeValues,
                                        IDictionary<string, Object> htmlAttributes)
 {
     var linkString = htmlHelper.ActionLink(guid, actionName, controllerName, routeValues, htmlAttributes);
     return ReplaceGuidWithRealText(linkText.ToString(), linkString);
 }

        public HelperResult RenderSection(string name, IHtmlString defaultContents)
        {
            if (this.IsSectionDefined(name))
            {
                return this.RenderSection(name);
            }

            var result = new HelperResult((x) => x.Write(defaultContents.ToString()));
            return this.RenderSection(name, (x) => result);
        }

 /// <summary>
 /// ����һ��MvcHtmlWrapper�������MvcHtmlWrapper��ֱ�ӷ��أ�
 /// �������������������MvcHtmlWrapper�