使用NVelocity模板引擎构建ASP.NET网站

        public interface IHandlerFactory    {        /// <summary>        /// 页面加载        /// </summary>        /// <param name="context"></param>        void Page_Load(ref VelocityContext context);        /// <summary>        /// 处理POST数据        /// </summary>        /// <param name="context"></param>        void Page_PostBack(ref VelocityContext context);    }    /// <summary>    /// NVelocity模板引擎成员类    /// </summary>    public class IHandler : IHttpHandler, IRequiresSessionState    {        /// <summary>        /// MVC操作        /// </summary>        /// <param name="context"></param>        public void ProcessRequest(HttpContext context)        {            string rootpath = context.Request.PhysicalApplicationPath;            string scriptpath = context.Request.PhysicalPath;            string filepath = scriptpath.Replace(rootpath, string.Empty);            string filename = filepath.ToLower().Replace("/", ".").Replace("\\", ".").Replace(".aspx", string.Empty);            string template = filename.Replace(".", "/") + ".html";  //获取当前请求页面所对应的html路径            string templatepath = "template\\default"; //html页面所在的文件夹根路径            string contentType = "text/html";            string http_Accept = context.Request.ServerVariables["HTTP_ACCEPT"];            VelocityEngine engine = new VelocityEngine();            engine.SetProperty(RuntimeConstants.RESOURCE_LOADER, "file");            engine.SetProperty(RuntimeConstants.FILE_RESOURCE_LOADER_PATH, rootpath + templatepath);  //设置引擎加载的文档所在的根路径            engine.Init();                     VelocityContext ctx = new VelocityContext();            string root = HttpContext.Current.Request.ApplicationPath;            if (root == "/") root = string.Empty;            ctx.Put("webpath", root);            //保存页面处理时需要的相关变量            IHandlerFactory factory = null;            try            {                factory = (IHandlerFactory)Assembly.Load("xxxx").CreateInstance("xxxx" + filename, true);  //创建当前请求页面的实例                if (factory == null)                {                    template = "error404.html";                }                else                {                    if (context.Request.HttpMethod == "POST" && !IsReSubmit(ref context, ref ctx))                    {                        factory.Page_PostBack(ref ctx);  //调用继承了该接口的请求页面的Page_PostBack方法                    }                    else                    {                        factory.Page_Load(ref ctx);  //调用继承了该接口的请求页面的Page_Load方法                    }                }            }            #region 异常            catch (InvalidCastException ex)            {                   //异常处理，记录错误日志                //template = "500.html";                          }            catch (Exception ex)            {                //异常出处理，记录错误日志               }            #endregion            //执行跳转的处理            if (ctx.Get("redirecturl") != null)            {                string redirecturl = ctx.Get("redirecturl").ToString();                context.Response.Redirect(redirecturl);            }            Template tpl = engine.GetTemplate(template);            StringWriter writer = new StringWriter();            tpl.Merge(ctx, writer);            context.Response.ContentType = contentType;            context.Response.Write(writer.GetStringBuilder().ToString());        }        /// <summary>        ///         /// </summary>        public bool IsReusable        {            get            {                return true;            }        }        /// <summary>        /// 是否重复提交        /// </summary>        /// <param name="context"></param>        /// <param name="ctx"></param>        /// <returns></returns>        private bool IsReSubmit(ref HttpContext context, ref VelocityContext ctx)        {            //获取上次提交的令牌            string token = context.Request.Cookies["token"] == null ? string.Empty : context.Request.Cookies["token"].Value;            //为表单签名            string newToken = Common.Input.MD5(context.Request.Form == null ? string.Empty : context.Request.Form.ToString());            //和上次的令牌比较            if (token != newToken)            {                context.Response.Cookies["token"].Value = newToken;                return false;            }            ctx.Put("errors", "不允许重复提交数据");            return true;        }    }