What's the difference between context.Get() and its generic version?

Question

I'm trying to get familiar with OWIN and there are a lot of things that confuse me. For example, in partial startup.cs class I register context callback via

app.CreatePerOwinContext(ApplicationDbContext.Create);
app.CreatePerOwinContext<ApplicationUserManager>(ApplicationUserManager.Create);

What's the difference? Why do we need that generic method?

I can get that context like this:

context.Get<ApplicationDbContext>())
context.GetUserManager<ApplicationUserManager>()

What's the difference between the Get and GetUserManager methods? Why can't I just call context.Get for ApplicationUserManager?

Answer 1

There is no difference between Get<UserManager> and GetUserManager<UserManager>

Here's the source code for both...

    /// <summary>
    ///     Retrieves an object from the OwinContext using a key based on the AssemblyQualified type name
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="context"></param>
    /// <returns></returns>
    public static T Get<T>(this IOwinContext context)
    {
        if (context == null)
        {
            throw new ArgumentNullException("context");
        }
        return context.Get<T>(GetKey(typeof (T)));
    }

    /// <summary>
    ///     Get the user manager from the context
    /// </summary>
    /// <typeparam name="TManager"></typeparam>
    /// <param name="context"></param>
    /// <returns></returns>
    public static TManager GetUserManager<TManager>(this IOwinContext context)
    {
        if (context == null)
        {
            throw new ArgumentNullException("context");
        }
        return context.Get<TManager>();
    }