How to Render Partial View into a String

Question

I have the following code:

public ActionResult SomeAction() {     return new JsonpResult     {         Data = new { Widget = "some partial html for the widget" }     }; } 

I'd like to modify it so that I could have

public ActionResult SomeAction() {     // will render HTML that I can pass to the JSONP result to return.     var partial = RenderPartial(viewModel);      return new JsonpResult     {         Data = new { Widget = partial }     }; } 

is this possible? Could somebody explain how?

note, I edited the question before posting the solution.

Answer 1

I opted for an extension method like the following for an ASP.NET MVC 4 app. I think it's simpler than some of the suggestions I've seen:

public static class ViewExtensions {     public static string RenderToString(this PartialViewResult partialView)     {         var httpContext = HttpContext.Current;          if (httpContext == null)         {             throw new NotSupportedException("An HTTP context is required to render the partial view to a string");         }          var controllerName = httpContext.Request.RequestContext.RouteData.Values["controller"].ToString();          var controller = (ControllerBase)ControllerBuilder.Current.GetControllerFactory().CreateController(httpContext.Request.RequestContext, controllerName);          var controllerContext = new ControllerContext(httpContext.Request.RequestContext, controller);          var view = ViewEngines.Engines.FindPartialView(controllerContext, partialView.ViewName).View;          var sb = new StringBuilder();          using (var sw = new StringWriter(sb))         {             using (var tw = new HtmlTextWriter(sw))             {                 view.Render(new ViewContext(controllerContext, view, partialView.ViewData, partialView.TempData, tw), tw);             }         }          return sb.ToString();     } } 

It allows me to do the following:

var html = PartialView("SomeView").RenderToString(); 

Also, this approach persists any Model, ViewBag and other view data for the view.

Answer 2

This is a slightly modified version of an answer that works:

public static string RenderPartialToString(string controlName, object viewData) {     ViewPage viewPage = new ViewPage() { ViewContext = new ViewContext() };      viewPage.ViewData = new ViewDataDictionary(viewData);     viewPage.Controls.Add(viewPage.LoadControl(controlName));      StringBuilder sb = new StringBuilder();     using (StringWriter sw = new StringWriter(sb))     {         using (HtmlTextWriter tw = new HtmlTextWriter(sw))         {             viewPage.RenderControl(tw);         }     }      return sb.ToString(); } 

Usage:

string ret = RenderPartialToString("~/Views/MyController/MyPartial.ascx", model);