LATEX: delete the number of page from the backmatter - latex

Question

im tring to delete the page number from my \backmatter sequence. I've succeded to do this, writing this code:
\begin{document}
.
.
.
\backmatter
\begingroup
\makeatletter
\let\ps#plain\ps#empty
\addcontentsline{toc}{chapter}{Allegati}
\input{Allegati}
\input{Bibliografia}
\listoffigures
\listoftables
\listof{grafico}{Elenco dei grafici}
\endgroup
\end{document}
But, I don't know why, the last page of my document still have his number. In the code above the last page is a graphic list, but if I change the order of my sequence, for example putting the bibliography in the last position, the this element will present the page number. I'm writing this document using the book class.
Someone can help me?
thanks

Answer 1

As you did not provide a MWE (Minimal Working Example) I can just guess what your document's preamble contains.
Have a look at this code please:
\documentclass{book}
\usepackage{fancyhdr}
\pagestyle{fancy}
\fancypagestyle{plain}{
\lhead{}
\chead{}
\rhead{}
\lfoot{}
\cfoot{}
\rfoot{}
}
\begin{document}
text
\newpage
text
\newpage
\backmatter
\begingroup
\pagestyle{plain}
\addcontentsline{toc}{chapter}{Allegati}
\listoffigures
\listoftables
%\listof{grafico}{Elenco dei grafici}
\endgroup
\end{document}
EDIT1:
This way you redefine the plain-style that is used by every chapter-page in your document.
If you do not want to change it document-wide, your approach is correct; just add a \clearpage before the last \endgroup. It won't create a new page, but delete the pagenumber. Btw, if you don't really need the \begingroup \endgroup leave it out, this will also delete the last page number.
END-EDIT1
A few things to note:
If you use plain book-class, you can use fancyhdr for setting a
page style like in the above example. Later just load the wanted
pagestyle and from there on it will be used.
If you want to write a document according to the modern
standard of LaTeX, maybe think about using a KOMA-class, which
provides great functions for changing the page style (and often they
also work better ;))
For me this MWE does work, having no pagenumber on the last page; if it does not for you, please give us more information about your document.