Hi Volker,
Thinking a bit more to your problem, there is a good solution to it
in ROOT 3.02/04 (thanks to Philippe).
Instead of using the function ProcessLine, use Calc.
Example
TObject *obj=(TObject*)gInterpreter.Calc("new TH1F(\"h\",\"h\",100,-3,3)")
obj->Draw();
Calc returns the result of the query as a Long_t. You just have to cast it
to the correct type, or simply a TObject* if you like.
Rene Brun
Rene Brun wrote:
>
> Hi Volker,
>
> Following a mail from Axel, I just realize that I misunderstood your question.
>
> Why do you want to call TClass::New to create a new object ?
> Why don't you call directly the class constructor?
>
> In case, you want to create an object when you know only the name ot its class
> (could be what you try to do?), you can use the interpreter ProcessLine,
> Example:
> gInterpreter.ProcessLine("new TH1F(\"h\",\"h\",100,-3,3)")
> will create a new TH1F object. In this particular case, you can retrieve
> a pointer to the created object via gDirectory->Get("h"): the TH1F constructor
> adding automatically a reference to the object in the list of objects
> of the current directory.
> You can modify your constructor to automatically register itself to some
> collection.
>
> Rene Brun
>
> Volker Hejny wrote:
> >
> > Hallo,
> >
> > if I have a class name as a string value at run time, it is possible
> > to construct a new object of this class using TClass::New(). That
> > way the standard constructor is called. Is there any way to call
> > a different constructor with a given argument?
> >
> > Best regards,
> > Volker
> >
> > --
> > Dr. Volker Hejny Tel: 02461/616853 **
> > Institut f. Kernphysik Fax: 02461/613930 **
> > ---------------------------------------------------------------- ** ** ---
> > Forschungszentrum Juelich GmbH, D-52425 Juelich **
This archive was generated by hypermail 2b29 : Tue Jan 01 2002 - 17:51:09 MET