CommonHelper

 public static string RanderHtml(string templateName, object data)
        {
            VelocityEngine vltEngine = new VelocityEngine();
            vltEngine.SetProperty(RuntimeConstants.RESOURCE_LOADER, "file");
            vltEngine.SetProperty(RuntimeConstants.FILE_RESOURCE_LOADER_PATH, System.Web.Hosting.HostingEnvironment.MapPath("~/templates"));
            vltEngine.Init();           
            VelocityContext vltContext = new VelocityContext();
            vltContext.Put("Data", data );

            Template vltTemplate = vltEngine.GetTemplate(templateName);
            System.IO.StringWriter vltWriter = new System.IO.StringWriter();
            vltTemplate.Merge(vltContext, vltWriter);
            string html = vltWriter.GetStringBuilder().ToString();
            return html;
        }