[Lazarus] TControl.Click?

Mattias Gaertner nc-gaertnma at netcologne.de
Sat Oct 1 15:00:22 CEST 2011


On Sat, 01 Oct 2011 15:21:41 +0200
Hans-Peter Diettrich <DrDiettrich1 at aol.com> wrote:

> Mattias Gaertner schrieb:
> 
> >>>>> "Assigned" is used instead of "FOnClick<>nil"
> >>>>
> >>>> What is different between check the Method fields ?
> >>>> "Assigned(FOnClick)" and "FOnClick<>nil"
> >>>
> >>> http://wiki.lazarus.freepascal.org/IDE_tricks#Events_.28Method_properties.29_in_the_Object_Inspector
> 
> >> Thanks, but not understand it, but i will to check and correct my components
> >> code.
> > 
> > What do you don't understand?
> 
> The many "Do not ..." hints are not really helpful without understanding 
> method pointers and Assigned().
> 
> In detail I supposed that FOnClick<>nil will never work properly, on no 
> method pointer, because it only checks the first pointer (explanation in 
> Delphi newsgroups).
> 
> The documentation of Assigned() also is not really helpful, there's no 
> explanation of the real difference vs. P<>nil. There seem to exist more 
> differences, e.g. with the "dummy" event handler value at design time?

This wiki page is not the documentation for methods in general. See the
fpc docs for that.
The wiki page is more like an FAQ.

Mattias




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