How do I clear the view file location cache used by the ViewEngine in ASP.Net MVC 3

Question

The ViewEngine in ASP.Net MVC 3 caches the physical paths of the views and partial views which is causing errors when I add or move view files in my production environment. Is there a way I can clear that cache at runtime? I found one article online that says that cache is stored in HttpContext.Cache, but I'm not sure which entry it is.

Answer 1

Here's the key used by the Razor view engine:

// System.Web.Mvc.VirtualPathProviderViewEngine
private string CreateCacheKey(string prefix, string name, string controllerName, string areaName)
{
    return string.Format(CultureInfo.InvariantCulture, ":ViewCacheEntry:{0}:{1}:{2}:{3}:{4}:", new object[]
    {
        base.GetType().AssemblyQualifiedName, 
        prefix, 
        name, 
        controllerName, 
        areaName
    });
}

So for example if you wanted to clear the cache location of the Index view for Home controller you would remove the following key from the HttpContext.Cache:

HttpContext.Cache.Remove(":ViewCacheEntry:System.Web.Mvc.RazorViewEngine, System.Web.Mvc, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35:View:Index:Home::");

and for the _LogOnPartial.cshtml partial:

HttpContext.Cache.Remove(":ViewCacheEntry:System.Web.Mvc.RazorViewEngine, System.Web.Mvc, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35:Partial:_LogOnPartial:Home::");

You should obviously be aware that you are using a totally undocumented feature that could be changed without any notice and your code could stop working in a future version of ASP.NET MVC.