We have an existing MVC2 project that we just upgraded to MVC4 following first these steps to get to MVC3, then these steps to get to MVC4.

Output caching had been successfully working for a long time in our MVC2 project, but it does not work after the MVC4 version.

I've added a simple controller to test caching:

 public class TestController : Controller
 {
    [OutputCache(Duration = 600, VaryByParam = "*")]
    public ActionResult CacheTest()
    {
        return Content(DateTime.Now.ToLongTimeString());
    }
 }

Each time i request /Test/CacheTest in a browser, the time output to the browser changes.

Creating a new MVC3 project in this same solution, then upgrading to MVC4, then copying this same code over works as expected.

So there must be something somewhere in our existing code or configuration that is breaking output caching.

I've also tried stripping out a ton of stuff from the web.config file thinking something there was causing problems - no luck.

Rendering the CacheTest action above in any view will display cached results - i.e. the date does not change on each refresh:

<% Html.RenderAction("CacheTest", "Test"); %>

Why does that work, but the action url from a browser is never cached?

Any suggestions on how to fix or debug?

Thanks.

Hi,

This definitely looks wrong - we'll investigate and see if we can figure out what's going on here.

Thanks,

Eilon

So it seems IsChildAction is not true when the OutputCacheAttribute.OnActionExecuting is being called, so caching is skipped.  This also explains why when i call Html.RenderAction caching works.

I could maybe understand some compatibility problems if i was still using the standard MVC2 Site.Master and aspx view engine (which i was and caching was not working).

However, i added a Razor _Layout.cshtml and a razor view to my project, and still no dice. 

Under what conditions should ControllerContext.IsChildAction be true when rendering an action?

@BradWilson

Thanks for the reply. 

Can you point me to some area in the code where a different caching path is taken?   The OnActionExecuting, OnResultExecuting, OnActionExecuted, and OnResultExecuted in OutputCacheAttribute all check filterContext.IsChildAction.

I also tried adding the OutputCache directive a view and the view is still not cached.

Hi, I have the same problem as jaminto.

Caching stopped working after upgrading of my project from MVC3 to MVC4!

Please is there any workaround? Did you solve the problem, jaminto?