See:
Try:
{
TFile *f = TFile::Open("selected.root");
if (!f) return; // just a precaution
TTree *t; f->GetObject("recData", t);
if (!t) { delete f; return; } // just a precaution
t->SetMakeClass(1);
t->SetBranchStatus("*", 0);
Int_t fFDEvents_;
// note: you must know kMaxevent_fFDEvents from somewhere else,
// e.g. use TTree::MakeClass to get it
const Int_t kMaxevent_fFDEvents = 3;
Double_t fEnergy[kMaxevent_fFDEvents]; //[fFDEvents_]
t->SetBranchStatus("event.fFDEvents", 1);
t->SetBranchAddress("event.fFDEvents", &fFDEvents_);
t->SetBranchStatus("event.fFDEvents.fFdRecShower.fEnergy", 1);
t->SetBranchAddress("event.fFDEvents.fFdRecShower.fEnergy", fEnergy);
for(Long64_t i = 0; i < t->GetEntries(); i++) {
t->GetEntry(i);
if (fFDEvents_ > kMaxevent_fFDEvents) {
// note: the stack is corrupt, a SIGSEV crash is possible
std::cout << i << " : " << fFDEvents_ << " :"
<< " FATAL ERROR : fFDEvents_ > kMaxevent_fFDEvents = "
<< kMaxevent_fFDEvents << std::endl;
delete f; // automatically deletes "t", too
return; // try to get out of here
}
std::cout << i << " : " << fFDEvents_ << " :";
for (Int_t j = 0; j < fFDEvents_; j++) std::cout << " " << fEnergy[j];
std::cout << std::endl;
}
// t->ResetBranchAddresses(); // detach "t" from local variables
delete f; // automatically deletes "t", too
}