Disposable Pattern

Disposable

public /*non-sealed*/ class Foo : IDisposable
{
    public /*implicitly sealed*/ void Dispose()
    {
        Console.WriteLine("Disposing Foo managed resources.");

        DisposeFooCore();
    }

    protected virtual void DisposeFooCore() { }
}

public /*non-sealed*/ class Bar : Foo
{
    protected sealed override void DisposeFooCore()
    {
        Console.WriteLine("Disposing Bar managed resources.");

        DisposeBarCore();
    }

    protected virtual void DisposeBarCore() { }
}

public sealed class Qux : Bar
{
    protected override void DisposeBarCore()
    {
        Console.WriteLine("Disposing Qux managed resources.");
    }
}

...

using (new Qux()) { }

// Output:
// Disposing Foo managed resources.
// Disposing Bar managed resources.
// Disposing Qux managed resources.