a reference to an Adapterinterface at the position specified by the Adapter parameter
解説
When you create a factory, the factory enumerates the set of adapters that are available in the system. Therefore, if you change the adapters in a system, you must destroy and recreate the Factoryobject. The number of adapters in a system changes when you add or remove a display card, or dock or undock a laptop.When the EnumAdapters method succeeds and fills the ppAdapter parameter with the address of the reference to the adapter interface, EnumAdapters increments the adapter interface's reference count. When you finish using the adapter interface, call the Release method to decrement the reference count before you destroy the reference.EnumAdapters first returns the local adapter with the output on which the desktop primary is displayed. This adapter corresponds with an index of zero. EnumAdapters then returns other adapters with outputs.