Perl 一个简单的 GUI 程序，有退出按钮

#!/usr/bin/perl -w

use Tk;

$Tk::strictMotif = 1;

$main = MainWindow->new();

$button1 = $main->Button(-text => "Exit",
                         -command => \&exit_button,
                         -foreground => "orangered" );

$button1->pack();
$button1->configure(-background => "white" );
$button2 = $main->Button(-text => "Push Me",
                         -command => \&change_color,
                         -foreground => "black", 
                         -background => "steelblue");

$button2->pack();

MainLoop();

sub exit_button {
    print "You pushed the button!\n";
    exit;
}

sub change_color {
    $button1->configure(-background => "red",
                        -foreground => "white");
    $button2->configure(-background => "maroon",
                        -foreground => "white",
                        -font       => "-*-times-bold-r-normal-20-140-*");
}