public static class RenderViewTostring

    {

        /// <summary>

        ///将部分视图转成html 字符串方便我们扩展使用

        /// </summary>

        /// <param name="controller">The controller.</param>

        /// <param name="viewName">Name of the view.</param>

        /// <param name="model">The model.</param>

        /// <returns></returns>

        public static string RenderPartialView(this Controller controller, string viewName)

        {

            return RenderPartialView(controller, viewName, null);

        }

        /// <summary>

        ///将部分视图转成html 字符串方便我们扩展使用

        /// </summary>

        /// <param name="controller">The controller.</param>

        /// <param name="viewName">Name of the view.</param>

        /// <param name="model">The model.</param>

        /// <returns></returns>

        public static string RenderPartialView(this Controller controller, string viewName, object model)

        {

            if (string.IsNullOrEmpty(viewName))

                viewName = controller.ControllerContext.RouteData.GetRequiredString("action");

            controller.ViewData.Model = model;

            using (var sw = new StringWriter())

            {

                ViewEngineResult viewResult = ViewEngines.Engines.FindPartialView(controller.ControllerContext, viewName);

                var viewContext = new ViewContext(controller.ControllerContext, viewResult.View, controller.ViewData, controller.TempData, sw);

                viewResult.View.Render(viewContext, sw);

                // return sw.Encoding.EncodingName;

                return sw.GetStringBuilder().ToString();

            }

        }

        /// <summary>

        /// 部分视图转成html

        /// viewbag 和viewdata 访问是相通的.

        /// ViewData["Hello"] = "Hello Boy!";

        /// view ViewBag.Hello 就是访问上面这个;

        /// </summary>

        /// <param name="controller">The controller.</param>

        /// <param name="viewName">Name of the view.</param>

        /// <param name="model">The model.</param>

        /// <param name="viewdataary">键值形式的对象</param>

        /// <returns></returns>

        public static string RenderPartialView(this Controller controller, string viewName, object model, params KeyValuePair<string, object>[] viewdataary)

        {

            if (string.IsNullOrEmpty(viewName))

                viewName = controller.ControllerContext.RouteData.GetRequiredString("action");

            controller.ViewData.Model = model;

            if (viewdataary != null && viewdataary.Any())

            {

                foreach (var item in viewdataary)

                {

                    controller.ViewData.Add(item);

                }

            }

            return ControllserRenderView(controller, viewName);

        }

        /// <summary>

        /// Controllsers the render view.

        /// </summary>

        /// <param name="controller">The controller.</param>

        /// <param name="viewName">Name of the view.</param>

        /// <returns></returns>

        private static string ControllserRenderView(Controller controller, string viewName)

        {

            using (var sw = new StringWriter())

            {

                ViewEngineResult viewResult = ViewEngines.Engines.FindPartialView(controller.ControllerContext, viewName);

                var viewContext = new ViewContext(controller.ControllerContext, viewResult.View, controller.ViewData, controller.TempData, sw);

                viewResult.View.Render(viewContext, sw);

                return sw.GetStringBuilder().ToString();

            }

        }

    }