Text on a pad

I would like to put some text on my pad

#include <TCanvas.h>
#include <TVirtualPad.h>
#include <TText.h>
#include <TGraph.h>
Int_t w = 800;
Int_t h = 400;

TCanvas *c1 = new TCanvas("c1", "c1", w, h);
c1->SetWindowSize( w+(w-c1->GetWw()), h+(h-c1->GetWh()) );

TGraph *g =....// some TGraph here
g->Draw("AP"); //it draws OK 

//now I would like to put some text  in my pad
TVirtualPad *c1_1 =c1;
(new TText(0.1, 0.5, "c1 ... 1 ... 1"))->Draw(); 

However I am not able to make the text appear in my pad.

Your macro is a bit bizarre … oh well why not …
I am not sure why you created this VirtualPad…
The way you create the text is a good also to confuse people … but why not if you like it …
Anyway without the graph the text is drawn.
I guess your graph defines some coordinate system which is such that 0.1 0.5 falls out of it