/// <summary>
        /// 获取html模版
        /// </summary>
        /// <param name="templateName">渲染的html模版的名称</param>
        /// <param name="data">渲染html的数据</param>
        /// <returns>渲染生成的html代码string类型</returns>
        public static string RenderHtml(string templateName, object data)
         {
             string rtn = string.Empty;
             VelocityEngine vltEngine = new VelocityEngine();
             vltEngine.SetProperty(RuntimeConstants.RESOURCE_LOADER, "file");
             vltEngine.SetProperty(RuntimeConstants.FILE_RESOURCE_LOADER_PATH, System.Web.Hosting.HostingEnvironment.MapPath("~/Templates"));//模板文件所在的文件夹
             vltEngine.Init();

             VelocityContext vltContext = new VelocityContext();
             vltContext.Put("data", data);//设置参数，在模板中可以通过$data来引用,可以同时设定多个参数
             Template vltTemplate = vltEngine.GetTemplate(templateName);
             System.IO.StringWriter vltWriter = new System.IO.StringWriter();
             vltTemplate.Merge(vltContext, vltWriter);

             rtn = vltWriter.GetStringBuilder().ToString();
             return rtn;
         }