In following the tutorial through Chapter 2, everything was cool until I hit step 3 on pages 44-5. When I run the program and visit "/Store/Details/5", I get an error complaining about a null parameter for int id.
If I make int id nullable: I don't see the error, but I id is not displayed in the output, either.
The output is displayed correctly if I visit "/Store/Detials?id=5".
"ASP.NET MVC's default routing convention is to treat the segment of a URL after the action method name as a parameter named ID." - has this behavior changed, do I need to change a setting in Visual Studio, or have I overlooked something?
Thanks in advance for any assistance.

"ID" should not be nullable - just by nature; which item you are referring to if its ID is null? And if there are several of them with null IDs?

Do not make ID nullable; look for the error in some other place before it;

If "/Store/Details/5" gets you a null parameter, may be something is wrong with your routing;

Oleg,

I created a new project and recreated everything, and did not get the error. I reexamined the old project and could not see what was wrong. I deleted the Store controller and recreated it. (In retrospect, I should not have deleted it. Now I can't figure out what was wrong. Live and learn.)

Works correctly now. All I can think is that I had a typo somewhere, even though I really read through it closely.

Thanks for your help. Cheers.

I had the same problem. It works OK so long as your variable is id in upper or lower case. Its type doesn't matter, but you can't use any other variable name such as productID.

You can use 'Id' without naming it because it's in your default routing:


routes.MapRoute(
name: "Default",
url: "{controller}/{action}/{id}",
defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional }
);


Otherwise you will need to specify the name of the parameter in order for the binding to find it and put into your incoming variables:

Browser: /Store/Details/?ProductId=5

MVC: public ActionResult Details(int ProductId)

I reexamined the old project and could not see what was wrong. I deleted the Store controller and recreated it. (In retrospect, I should not have deleted it. Now I can't figure out what was wrong. Live and learn.)