Question

Visual Studio 2010, .Net 4.0

I’m generating some Domain Service Classes and this is how visual studio includes the namespaces:

namespace MyCoolProject.Web.Services
{
    using System;
    using System.Collections.Generic;
    using System.ComponentModel;
    using System.ComponentModel.DataAnnotations;
    using System.Data.Linq;
    using System.Linq;
    using System.ServiceModel.DomainServices.Hosting;
    using System.ServiceModel.DomainServices.Server;
    using Columbus.Web.Data;
    using Microsoft.ServiceModel.DomainServices.LinqToSql;


    // Implements application logic using the JanDoetsDataContext context.
    // TODO: Add your application logic to these methods or in additional methods.
    // TODO: Wire up authentication (Windows/ASP.NET Forms) and uncomment the following to disable anonymous access
    // Also consider adding roles to restrict access as appropriate.
    // [RequiresAuthentication]
    [EnableClientAccess()]
    public class AnnouncementService : LinqToSqlDomainService<MydataDataContext>
    {......................

the namespaces needed by this class are included inside the namespace declaration, in other words the using bla bla bla lines are inside the MyCoolProject.Web.Services namespace declaration and not outside. Is this a new convention or a vs2010 bug?

Answer 1

Placing using directives inside a namespace is possible since .NET 1.0. This is done to avoid namespace polution because the types include by the using directives are only visible inside the namespace containing the using statements. So they just changed the code generator to adhere to the recommended practice to put using directives in the deepest possible namespace. Placing the the using directives outside any namespace performs the include in the global root namespace.

Have a look at StyleCop rule SA1200 for some more details.

UPDATE

The answer is a bit unprecise – the placement of the using directive is a C# thing and therefore it should read “is possible since C# 1.0” instead of “is possible since .NET 1.0”.