private bool ViewExists(string name) {     return ViewEngines.Engines.FindView(         ControllerContext, name, "").View != null; } 

The answer from Darin Dimitrov got me an idea.

I think it would be best to do just this:

public class HomeController : Controller {     public ActionResult View(string name) {         return new ViewResultWithHttpNotFound { ViewName = name};     } } 

having a new type of action result:

    public class ViewResultWithHttpNotFound : ViewResult {          protected override ViewEngineResult FindView(ControllerContext context) {             ViewEngineResult result = ViewEngineCollection.FindView(context, ViewName, MasterName);             if (result.View == null)                 throw new HttpException(404, "Not Found");             return result;               }      }