internal static MvcHtmlString LabelHelper(HtmlHelper html, ModelMetadata metadata, string htmlFieldName, string labelText = null, IDictionary htmlAttributes = null) { string resolvedLabelText = labelText ?? metadata.DisplayName ?? metadata.PropertyName ?? htmlFieldName.Split('.').Last(); if (String.IsNullOrEmpty(resolvedLabelText)) { return MvcHtmlString.Empty; } TagBuilder tag = new TagBuilder("label"); tag.Attributes.Add("for", TagBuilder.CreateSanitizedId(html.ViewContext.ViewData.TemplateInfo.GetFullHtmlFieldName(htmlFieldName))); tag.SetInnerText(resolvedLabelText); tag.MergeAttributes(htmlAttributes, replaceExisting: true); return tag.ToMvcHtmlString(TagRenderMode.Normal); }

using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.Mvc; namespace MvcHtmlHelper.Helper { /// 
 /// HTML的扩展类 /// 
 public static class HtmlHelperExt { /// 
 /// 用C#代码自定义一个span标签的扩展方法 /// 
 ///  ///  ///  ///  ///  ///  public static MvcHtmlString Messager(this HtmlHelper htlper, string id,string name, string style, object message) { if (message != null) { TagBuilder builder = new TagBuilder("span"); builder.MergeAttribute("style", style); //定义样式 builder.MergeAttribute("id", id); // 定义Id builder.MergeAttribute("name", name); // 定义name builder.SetInnerText(message.ToString()); //ToMvcHtmlString是在TagBuilderExtensions扩展类中定义的 return builder.ToMvcHtmlString(TagRenderMode.Normal); } return MvcHtmlString.Empty; } } }

using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.Mvc; namespace MvcHtmlHelper.Helper { public static class TagBuilderExtensions { public static MvcHtmlString ToMvcHtmlString(this TagBuilder tagBuilder, TagRenderMode renderMode) { System.Diagnostics.Debug.Assert(tagBuilder != null); return new MvcHtmlString(tagBuilder.ToString(renderMode)); } } }

@using MvcHtmlHelper.Helper; @{ ViewBag.Title = "Home Page"; } 
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 @Html.Messager("lblMessage", "lblMessage", "color:red;font-weight:bold;", "自定义span标签") 
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