[fpc-pascal] support for using anactivex

[Ludo Brands]

Use Item(i). Item(long Index, [out, retval] ITransducer* *pVal); means
method with 1 input Index and Output Itransducer^.

Ludo  

> -----Message d'origine-----
> De : fpc-pascal-bounces at lists.freepascal.org 
> [mailto:fpc-pascal-bounces at lists.freepascal.org] De la part 
> de Roberto Padovani
> Envoyé : lundi 30 mai 2011 14:16
> À : FPC-Pascal users discussions
> Objet : Re: RE : RE : RE : RE : RE : RE : [fpc-pascal] 
> support for using anactivex
> 
> 
> Hi Ludo,
> 
> I really cannot get the items to work. I simplyfied the 
> source code to the minimum in order to test the items stuff.
> 
> var   obj, item, items : variant;
> 
> obj := CreateOleObject('WRGactiveX.Device');      // OK
> items := obj.Transducers;                                   // OK
> writeln('Count: ', items.Count);                             // OK ,
> always prints 8
> 
> item := items.item[1];             // Crash: EOleSysError : Numero di
> parametri non valido.
> 
> Where the exception comment translates to "wrong number of 
> parameters". Instead, writing item := items[1]  gives the 
> exception EVariantInvalidArgError : Invalid argument: Dispatch
> 
> In the activex source code I hav these interface declarations:
> 
> interface ITransducer : IDispatch
> 	{
> 		[propget, id(1), helpstring("property Name")] 
> HRESULT Name([out, retval] BSTR *pVal);
> 		[propget, id(2), helpstring("property Status")] 
> HRESULT Status([out, retval] WRG_TransdStatus *pVal);
> 		[propget, id(4), helpstring("property Meas")] 
> HRESULT Meas([out, retval] double *pVal);
> 	};
> 	
> interface ITransducers : IDispatch
> 	{
> 		[propget, id(1), helpstring("property Count")] 
> HRESULT Count([out, retval] long *pVal);
> 		[propget, id(DISPID_VALUE), 
> helpstring("property Item")] HRESULT Item(long Index, [out, 
> retval] ITransducer* *pVal);
> 		[propget, id(DISPID_NEWENUM), 
> helpstring("property _NewEnum"), hidden] HRESULT 
> _NewEnum([out, retval] LPUNKNOWN *pVal);
> 	};
> 
> and used inside the IDevice class like:
> 
> 		[propget, id(21), helpstring("property 
> Transducers")] HRESULT Transducers([out, retval] ITransducers* *pVal);
> 
> 
> I would be very grateful if you could help me once more.
> 
> Roberto
> 
> 
> 
> 2011/5/25 Ludo Brands <ludo.brands at free.fr>:
> > Using variants you can transparently "walk" along the 
> exposed objects. 
> > The variant contains the Idispatch of the object and gets 
> the exposed 
> > methods at runtime. Properties are implemented as get and 
> put methods 
> > or just get methods for read only properties.
> >
> > If you have something like
> > Itransducers = interface
> >  ..
> >  property transducer[Index:integer]:Itransducer;
> > end;
> >
> > Then you would do
> > transducer := transducers.transducer[index];
> >
> > transducer := transducers[index];  works only if transducer is the 
> > default property for Itransducers. I'm not sure if fpc 
> supports this.
> >
> > Ludo
> >
> >
> > -----Message d'origine-----
> > De : fpc-pascal-bounces at lists.freepascal.org
> > [mailto:fpc-pascal-bounces at lists.freepascal.org] De la part 
> de Roberto 
> > Padovani Envoyé : mercredi 25 mai 2011 19:34
> > À : FPC-Pascal users discussions
> > Objet : Re: RE : RE : RE : RE : RE : [fpc-pascal] support 
> for using an
> > activex
> >
> >
> > 2011/5/25 Ludo Brands <ludo.brands at free.fr>:
> >> The code in article 
> >> 
> http://www.informit.com/articles/article.aspx?p=130494&seqNum=5 goes 
> >> a long way in doing what you want to do. Unit Eventsink 
> does pretty 
> >> much of the legwork. You should remove the procedure 
> register since 
> >> that is the Delphi way to get a component on the toolbar. 
> Remove also 
> >> the {$IFDEF VER100} and {$ENDIF}. The unit actually 
> includes the code 
> >> for InterfaceConnect!!
> >
> > found that! great!
> >
> >
> >> As for the tlb conversion, in your case
> >>
> >> IEventIntfEvents = dispinterface
> >>  ['{168F5642-5751-49F5-9AA4-B8A7A5F6A5B8}']
> >>  end;
> >>
> >> should do (that is for the events part). AFAIK the procedure and 
> >> dispid definitions are only needed for the server. You are only 
> >> concerned with dispid's. No need to create prototypes for
> >> OnCommChanged() etc. EventSink1Invoke would be a simple 
> case DispID 
> >> of
> >>  1: // do CommChanged
> >>  2: // do StatesChanged
> >> ...
> >> end;
> >>
> >>
> >
> > Now I am "wasting" time making the tlb pascal definitions. For the 
> > event part I'm fine with the dispid's Until now I was calling the 
> > activex method with variants, in and out, but now I discovered that 
> > this IDevice class has a property like: property
> > Sensors: ISensors;
> > which inside is a list of items like   Sensor: ISensor.
> >
> > Can I read the sensores with a variant? Then, to see the 
> fields inside 
> > each sensor, I think a I need a class to do that... The activex has 
> > all of these classes with the suitable dispinterfaces and 
> uuids and so 
> > on. But if I define
> >     var device, transducers, transducer : variant;
> > and create
> >     device := CreateOleObject('Device');
> > then, can i simply write the following ?
> >     transducers := device.Transducers;
> >     transducer := transducers[index];
> >
> >
> > It's a long path until I get this stuff working...
> >
> > R#
> > _______________________________________________
> > fpc-pascal maillist  -  fpc-pascal at lists.freepascal.org 
> > http://lists.freepascal.org/mailman/listinfo/fpc-pascal
> >
> > _______________________________________________
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> >
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