Correct scope of using using

Question

I'm in a quarrel with a colleague regarding the appropriate scope of the using statement. This is the method in question.

public Guid IsServerReachable()
{
  try
  {
    WhoAmIResponse whoAmI;
    using (OrganizationServiceProxy service = GetService())
      whoAmI = service.Execute(new WhoAmIRequest()) as WhoAmIResponse;
    return whoAmI.UserId;
  }
  catch { return Guid.Empty; }
}

One of us claims that the using statement should include the declaration of whyAmI, while the other argues that it's only the service instance that needs to be using-ified. I'm not telling which is my theory but one is clearly wrong. Which?

Answer 1

using (OrganizationServiceProxy service = GetService())
    whoAmI = service.Execute(new WhoAmIRequest()) as WhoAmIResponse;

Will be equivalent to:

OrganizationServiceProxy service = GetService();
try
{
    whoAmI = service.Execute(new WhoAmIRequest()) as WhoAmIResponse;
}
finally
{
    if (myRes!= null)
        // Call the object's Dispose method.
        ((IDisposable)service).Dispose();
}