StructureMap2_HttpContext.cs

// This is StructureMap 2.x
using StructureMap;

public static class IoC {
    public static IContainer Initialize() {
        ObjectFactory.Initialize(x =>
        {
          // ... snip ...

          x.For<IDbConnection>().HttpContextScoped().Use(GetConnection);
        });
        return ObjectFactory.Container;
    }
    static SqlConnection GetConnection()
    {
      // .. return a SqlConnection or whatever
    }
}

StructureMap3_HttpContext.cs

// This is StructureMap 3.x with StructureMap.Web
using StructureMap;
using StructureMap.Web.Pipeline;

public static class IoC {
	public static IContainer Initialize() {
		ObjectFactory.Initialize(x =>
		{
		  // ... snip ...

			x.For<IDbConnection>().Use("Getting Sql Connection", GetConnection).LifecycleIs<HttpContextLifecycle>();
		});
		return ObjectFactory.Container;
	}
  static IDbConnection GetConnection()
  {
    // .. return a SqlConection or whatever
  }
}