Xiangrong Fang schrieb:
OK, What confused me is the description found in FPC manual saying:
TInterfacedObject is a descendent of TObject
<http://www.freepascal.org/docs-html/rtl/system/tobject.html> which
implements the IUnknown
<http://www.freepascal.org/docs-html/rtl/system/iunknown.html>
interface. It can be used as a base class for all classes which need
reference counting.
in another word, reference counting is a feature of TInterfacedObject,
or the AfterConstruction/BeforeDestruction methods?? it sounds like
non-descedants of TInterfacedObject are not reference counted??
TInterfacedObject *simplifies* the addition of interfaces to derived
classes, by adding the required interface supporting methods to this
base class. For other classes, which are not based on TInterfacedObject,
adding interfaces requires that the interface support methods are added
explicitly to *every* such class.
The compiler inserts calls to the reference counting methods only when
an interface of a class is *really* used in code. Adding such methods to
other classes is of no use, because there these methods will never be
called.
DoDi
--
_______________________________________________
Lazarus mailing list
[email protected]
http://lists.lazarus.freepascal.org/mailman/listinfo/lazarus
