Queryable attribute is not compiling in mvc 4 web

问题:

I'm using MVC 4 web api that comes with visual studio 2012.

As I've understand odata is not parsed automatically, but we need to add [Queryable] attribute to the action now.

So I added it:

public class TestController : ApiController
{
    [Queryable]
    public IQueryable<MyClass> GetMyClasses()
    {
       return ...;
    }
}

but I'm getting a compilation error:

The type or namespace name 'Queryable' could not be found (are you missing a using directive or an assembly reference?) 

Is the odata still supported? and why Queryable is not recognized as an attribute as listed here.

Thank you

回答1:

As explained here, OData support has been moved to a separate NuGet package.

回答2:

It's in this Assembly (DLL) :

 System.Web.Http.OData.dll

This namespace :

System.Web.Http.QueryableAttribute

In this nuget package :

Install-Package Microsoft.AspNet.WebApi.OData

When I installed the package however it didn't appear as a valid type. Even verifying that System.Web.Http.OData.dll was present and looking in Object Explorer I couldn't find it. Eventually I just restarted Visual Studio and everything was fine. I suspect some older version of this DLL may have been confusing it or something like that.