Perl Tk label references

thimes has asked for the wisdom of the Perl Monks concerning the following question:

I have a problem with using a hash reference and updating a Label in PerlTk. It has to be something simple I am missing so I need some more eyes on the problem. This is a test program of a much larger one. Any help would be great! </p?

use Tk;
require Tk::Entry;
require Tk::Button;

my $mw = MainWindow->new();

my %work = (
    "VM-1" => "da923",
    "VM-2" => "dz427");

main_display(\%work);

MainLoop;

# -----------------------------------------------------
sub main_display {
    my $ref_hash = shift(@_);

    my $lab1 = $mw->Label(-textvariable => \$ref_hash{'VM-1'},
                                            -relief => 'sunken',
                                            -width => 10,
                                            )->pack();
    my $lab2 = $mw->Label(-textvariable => \$ref_hash{'VM-2'},
                                            -relief => 'sunken',
                                            -width => 10,
                                                )->pack();
    my $but = $mw->Button(-text=>'clear', -command=> [sub{
                                          $ref_hash = {};
                                          $mw -> update;
                                           }] )->pack();

}
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Comment on Perl Tk label references Download Code

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Re: Perl Tk label references by Anonymous Monk on Nov 10, 2016 at 21:29 UTC
Hi, do you see the problem now? `$ perl -le" $ref = {}; print $ref; $ref = {}; print $ref; $ref = {}; p +rint $ref; " HASH(0x3f9ac4) HASH(0x3f9b94) HASH(0x3f9ba4)` [download]	[reply] [d/l]
Re^2: Perl Tk label references by thimes (Acolyte) on Nov 10, 2016 at 21:40 UTC
No, sorry.	[reply]
Re^3: Perl Tk label references by thimes (Acolyte) on Nov 10, 2016 at 22:07 UTC
I was able to fix one problem. the Label reference syntax was wrong. The correct way was \$$ref_hash{'VM-1'}. But the clear of the hash when I click on the "clear" button still does not update my Label?? use Tk; require Tk::Entry; require Tk::Button; my $mw = MainWindow->new(); my %work = ( "VM-1" => "da923", "VM-2" => "dz427"); main_display(\%work); MainLoop; # ----------------------------------------------------- sub main_display { my $ref_hash = shift(@_); my $lab1 = $mw->Label(-textvariable => \$$ref_hash{'VM-1'}, -relief => 'sunken', -width => 10, )->pack(); my $lab2 = $mw->Label(-textvariable => \$$ref_hash{'VM-2'}, -relief => 'sunken', -width => 10, )->pack(); my $but = $mw->Button(-text=>'clear', -command=> [sub{ %{$ref_hash} = (); $mw -> update; }] )->pack(); } [download]	[reply] [d/l]
Re^4: Perl Tk label references by pryrt (Abbot) on Nov 10, 2016 at 22:17 UTC
Re^5: Perl Tk label references by pryrt (Abbot) on Nov 10, 2016 at 22:20 UTC
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Re^4: Perl Tk label references by Marshall (Canon) on Nov 10, 2016 at 22:52 UTC
Re^3: Perl Tk label references by Anonymous Monk on Nov 10, 2016 at 22:44 UTC
Ok, try now larry HASH(0x3f9ac4) curly HASH(0x3f9b94) shemp HASH(0x3f9ba4) $ref is larry , but then its curly, and then its shemp changing shemp or curly does not change larry, because larry is not curly or shemp	[reply]