If one object wraps (creates) another object inheriting from the IDisposable interface, it must implement the IDisposable interface, as in the example below:

class UsingIDisposable: IDisposable
{
   private Stream m_Stream;
   //
   // ...
   //
}

The object's end of life is immediately handled by calling the Dispose method if it:

• implements the IDisposable interface, and
• is created by the using statement, and
• the block of the instruction has ended.

The object end of life is immediately handled and the resources released if it:

• implements the interface IDisposable
• and the method Dispose is called in the program

If no program variable has references to it the object is immediately deleted and resources associated with it are released.

The object does not have to be manually deleted using the IDisposable.Dispose method or by using the using statement if we release external resources via other methods of this object, eg Stream.Close.