gROOT is null. Can someone help?

ROOT
1

Hi,
I’m a beginner in ROOT. I use visual studio 2010 and I try to dynamically load the needed ROOT libs into my program.

here is a code fragment from my code.

#include <TROOT.h>
int foo() {
gROOT->Reset();
}
The call to gROOT->Reset() fails because the gROOT var is null. Can you please help me understand why ?
I’ve loaded libCore.lib into the program and I was able to create some other classes.

Please help…
Thanks
Idan

2

Hi Idan,

I do not know how gROOT could null as it is initialized when libCore.dll is loaded. However you should also never call gROOT->Reset() from within a function ; it is intended to be used only in unnamed macros.

Philippe.

3

If I add TApplication::CreateApplication(); to the code before using gROOT than everything is working fine.
Can someone explain me why? is it the right thing to do?

Thanks
Idan

4

Hi,

There is an order of initialization problem (probably induced by the way you link you application). The call to TApplication::CreateApplication force the creation of the TROOT object and thus the setting of gROOT.

Philippe.