$file $x $y are three undefined variables -- wx will complain

This works for me on windows

$frame->DragAcceptFiles(1);
EVT_DROP_FILES( $frame, \&doit );
sub doit { warn "@_\n" }
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Why that?

use ...
Main( @ARGV );
exit( 0 );
...
sub
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Another thing i am trying to figure out is how to share a variable from a subroutine and pass it to print in the listbox?

What "subroutine", what variable where and for what purpose? The same principles apply to wxPerl, see write Tk callbacks all lexically scoped and not-memory leaking with no nested subs ever :) avoid nested subs and closures because nested named subs because they're closures

You register event handlers UPON widget objects (wxWindow a wxObject), so each event handler gets as first argument that wxObject ... there is even a global Wx::wxTheApp() which you can also use as a stash (better if the frames keep track of their own data) ... more words and/or more code gets more clear answer