That is correct. I am using the method suggested in this forum post. I had to remove the const modifier from the TFile argument in reading because ReadKeys is not marked as const (see error below).
I tried omitting delete file->FindObject(name);, but end up with this error
Error in <TFile::ReadKeys>: reading illegal key, exiting after 1 keys
If I use the method described in this response, then I can view histograms as expected.
I should note that I’ve also read the the threads here and here.
Error when using const TFile
In file included from input_line_12:9:
././viewOnline.C:11:9: error: member function 'ReadKeys' not viable: 'this' argument has type 'const TFile', but function is not marked const
file->ReadKeys();
^~~~
/opt/root/v6-11-02-1447-g38586de/include/TDirectoryFile.h:105:24: note: 'ReadKeys' declared here
virtual Int_t ReadKeys(Bool_t forceRead=kTRUE);
^
In file included from input_line_12:9:
././viewOnline.C:13:15: error: no matching member function for call to 'GetObject'
file->GetObject(name, hist1);
~~~~~~^~~~~~~~~
/opt/root/v6-11-02-1447-g38586de/include/TDirectoryFile.h:78:35: note: candidate function not viable: no known conversion from 'const TFile' to 'TDirectoryFile' for object argument
template <class T> inline void GetObject(const char* namecycle, T*& ptr) // See TDirectory::Get for i...