Default values for route parameters

All you need to do is decorate the parameters with [FromRoute]. 
[RequireRouteParameters] is used for overloaded actions methods that do not have any other disambiguation attribute (e.g. [HttpGet], [HttpPost], etc.)

Note that when using [FromRoute] on the default action (Index) the route will include the Index segment, e.g. Controller/Index/{stringVar}/{intVar}, if what you want is to exclude the Index segment you need to use the [CustomRoute] attribute like this:

[CustomRoute("{stringVar}/{intVar}")]
public ActionResult Index([FromRoute]string stringVar = null, [FromRoute]int intVar = 1) {
   ...
}

Let me know if this helps.

Thanks for your reply..I've tried that, but with no luck. I still get the 404 error message.

Can you show me the route definition (in routes.axd) ?

How can I see that? I was trying to find this file too..It seems silly but I can't find it..

If you installed MvcCodeRouting using NuGet then it should be in the web.config, else you have to add this:

   <system.web>
      <httpHandlers>
         <add path="routes.axd" verb="GET,HEAD" type="MvcCodeRouting.RouteDebugHandler, MvcCodeRouting"/>
      </httpHandlers>
   </system.web>
   <system.webServer>
      <validation validateIntegratedModeConfiguration="false"/>
      <handlers>
         <add name="MvcCodeRouting.RouteDebugHandler" path="routes.axd" verb="GET,HEAD" type="MvcCodeRouting.RouteDebugHandler, MvcCodeRouting"/>
      </handlers>
   </system.webServer>

Then visit http://localhost/MyApp/routes.axd

the portion is already in my web.config but I don't have the routes.axd file. My web.config has <compilation debug="true"/> and I've published it to iis with debug configuration. Am I doing something wrong? 

There is no routes.axd file, just navigate to ~/routes.axd

OK, I got it. With 

[CustomRoute("{stringVar}/{inVar}")]

public ActionResult Index([FromRoute]string stringVar= null, [FromRoute]int intVar= 1)

I get the following rule in routes.axd

routes.MapRoute(null,"{stringVar}/{intVar}", new { controller = @"Controller", action = @"Index", intVar= UrlParameter.Optional }, new { intVar = @"(0|-?[1-9]\d*)?" }, new[] { "MyApp.Controllers" }); 

That's weird, what is category and page doing there?

That was my mistake. I've corrected the post and fixed it in my project too but with no change, still 404.

For some reason stringVar is not considered optional, does it work if you visit ~/foo ?

Yes, it does..

It does that for every optional string route variable. I tried it with others too.

OK, stringVar should be optional, but when set to null it doesn't work, if you set to any other value e.g. stringVar ="" it works. I'll try to fix this if possible.

It works with "" .I thought that I have tried that, but now it worked. Thanks for your help!