解决MVC项目中，静态html 未找到时候，404的跳转

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Web;
using System.Web.Routing;

namespace WebClientService.Modules
{
    public class GateKeeperOfStaticHtml : IHttpModule
    {
        // Fields
        private static readonly object _contextKey = new object();
        private static readonly object _requestDataKey = new object();
        private RouteCollection _routeCollection;

        // Properties
        public RouteCollection RouteCollection
        {
            get
            {
                if (this._routeCollection == null)
                {
                    this._routeCollection = RouteTable.Routes;
                }
                return this._routeCollection;
            }
            set
            {
                this._routeCollection = value;
            }
        }

        public void Init(HttpApplication application)
        {

            if (application.Context.Items[_contextKey] == null)
            {
                application.Context.Items[_contextKey] = _contextKey;
                application.PostResolveRequestCache += new EventHandler(this.OnApplicationPostResolveRequestCache);
            }

        }

        private void OnApplicationPostResolveRequestCache(object sender, EventArgs e)
        {
            HttpContextBase context = new HttpContextWrapper(((HttpApplication)sender).Context);
            this.PostResolveRequestCache(context);
        }

        /// <summary>
        /// 检测是否是合法的处理后缀类型
        /// </summary>
        /// <param name="toCheckedStr"></param>
        /// <returns></returns>
        private bool IsValidExtension(string toCheckedStr) {
            bool result = false;
            if (string.IsNullOrEmpty(toCheckedStr))
            {
                result= false;
            }
            if (toCheckedStr.EndsWith(".html", StringComparison.CurrentCultureIgnoreCase)|| toCheckedStr.EndsWith(".htm", StringComparison.CurrentCultureIgnoreCase))
            {
                result= true;
            }

            return result;
        }

        public virtual void PostResolveRequestCache(HttpContextBase context)
        {

            RouteData routeData = this.RouteCollection.GetRouteData(context);
            if (routeData != null)
            {
                //检测路由数据，仅仅监听 html  资源
                var controller = routeData.Values.FirstOrDefault(x => x.Key == "controller");
                if (default(KeyValuePair<string,object>).Equals(controller))
                {
                    //没有控制器数据 不做处理
                    return;
                }
                //检测路由控制器的后缀，是否是 *****.html 或者 *****.htm的格式
                if (controller.Value==null)
                {
                    return;
                }

                if (!this.IsValidExtension(controller.Value.ToString()))
                {
                    return;
                }

                IRouteHandler routeHandler = routeData.RouteHandler;
                if (routeHandler == null)
                {
                    return;
                }

                if (!(routeHandler is StopRoutingHandler))
                {
                    RequestContext requestContext = new RequestContext(context, routeData);
                    context.Request.RequestContext = requestContext;
                    IHttpHandler httpHandler = routeHandler.GetHttpHandler(requestContext);
                    if (httpHandler == null)
                    {
                        return;
                    }

                    try
                    {

                        context.RemapHandler(httpHandler);

                    }
                    catch (Exception ex)
                    {
                        throw ex;
                    }

                }
            }

        }

        public void Dispose()
        {
            throw new NotImplementedException();
        }

    }
}

2 注册默认的错误页面

<customErrors defaultRedirect="defaultError.html" mode="On">
<error statusCode="404" redirect="404notfind.html"/>
</customErrors>

</system.web>

3 注册模块

<modules>
<remove name="FormsAuthentication"/>
<add name ="GateKeeper" type="WebClientService.Modules.GateKeeperOfStaticHtml,WebClientService"/>
</modules>