C# Anonymous Object Tip

I was in the middle of writing a URL helper for the default route in MVC, with this signature:

static string Default(this UrlHelper url, string controller, string action, object id)

My initial implementation looked like this:

static string Default(this UrlHelper url, string controller, string action, object id)
{
    return url.RouteUrl("default", new { controller = controller,
                                         action = action,
                                         id = id });
}

That's when Resharper chimed in and grayed some things out for me, teaching me a new trick: If you want your anonymous object field names to be the same as the value you're passing in, you don't need the name.

The abbreviated version looks like this:

static string Default(this UrlHelper url, string controller, string action, object id)
{
    return url.RouteUrl("default", new { controller, action, id });
}

Comments

[Haacked]

Slick! I often do something similar all the time in action methods where I want to redirect but pass along the id. Sounds like I can do this now:

return RedirectToAction("Foo", new {id});

DRY Baby!!!

[Chris sutton]

Very nice, didn't realize you could leave off the names like that.

Chris

[Chris Hardy]

Cash back!

[Mark Brackett]

Argh. If only it'd capitalize them for me, I'd be so happy. But, still a nice tip to save some typing.

[Andrey]

How I should write the method that it can take that parameter?

[Robert]

This can be used in LINQ as well

[Louis DeJardin]

Yeah! Same thing happened to me a few days ago.

At first I had an urge to be explicit and keep the name, but I just let it go.