RowNumber in RTC Report

Hi to All,

I want to make a RowNumber in RTC Report . I put this code on Report Code propertis:

Public RowNumber as Integer
Public Function SetRowNo
RowNumber=RowNumber+1
End Function

Public Function GetRowNo
Return RowNumber
End Function

and when I click print preview it works fine (picture 1)

but when I save report as PDF doesn't work (picture 2)


I use NAV 2016
Any advice,
Thanks a lot