delphi - I am trying to create a simple chat program by writing to a shared file on my network -

i trying use timer check the timestamp of file check if has been modified, if true must add line text file richedit. problem continually adds line richedit every 1/4 second (timer interval). have tried different methods can't right.

procedure tform1.timer1timer(sender: tobject); var filet : textfile; filename, readtxt : string; filedate1, filedate2 : integer; begin  assignfile(filet, 's:\share.talk'); filename := 's:\share.talk'; filedate1 := fileage(filename);  if filedate1 <> filedate2 begin reset(filet); readln(filet, readtxt); richedit1.lines.add(readtxt); closefile(filet); filedate2 := filedate1; end;//if end; 

thanks help.

in code

if filedate1 <> filedate2 begin reset(filet); readln(filet, readtxt); richedit1.lines.add(readtxt); closefile(filet); filedate2 := filedate1; end; 

the comparison between filedate , filedate2 assumes these retain values between calls timer1timer. not, because declared local timer1timer , therefore 'forgotten' between calls because stored on stack.

to them retain values, remove declaration on them local timer1timer , declare them fields of tform1 instead.

btw, aware design, going run other issues, how handle concurrent access network textfile, etc, not related specific point asked about.