package ABC;
use strict;
use warnings;
use base 'Exporter';
sub import{
strict->import;
warnings->import;
__PACKAGE__->export_to_level(1, @_);
}
1;
#!/usr/bin/perl
use feature ":5.10";
use ABC;
$undefined_var = "undefined var";
$ perl test.pl
Global symbol "$undefined_var" requires explicit package name at test.pl line 5.
package Apache2::Hello;
use strict;
use Apache2::RequestRec (); # for $r->content_type
use Apache2::RequestIO (); # for $r->puts
use Apache2::Const -compile => ':common';
sub handler {
my $r = shift;
my $time = scalar localtime();
my $package = __PACKAGE__;
$r->content_type('text/html');
$r->puts(<<"END");
<HTML><BODY>
<H3>Hello</H3> Hello from <B>$package</B>!
The time is $time.
</BODY></HTML>
END
return Apache2::Const::OK;
}
1;
use strict;
use lib qw(/path/to/module/);
use Apache::Hello;
$ENV{MOD_PERL} or die "not running under mod_perl!";
PerlRequire /path/to/startup.pl
SetHandler modperl
PerlHandler Apache2::Hello
/path/to/startup.pl
/path/to/Apache2/Hello.pm
package BankAccount;
use Moose;
has 'balance' => (isa => 'Int', is => 'rw', default => 0);
sub deposit {
my ($self, $amount) = @_;
$self->balance($self->balance + $amount);
}
sub withdraw {
my ($self, $amount) = @_;
my $current_balance = $self->balance();
($current_balance >= $amount)
|| confess "Account overdrawn";
$self->balance($current_balance - $amount);
}
package CheckingAccount;
use Moose;
extends 'BankAccount';
has 'overdraft_account' => (isa => 'BankAccount', is => 'rw');
before 'withdraw' => sub {
my ($self, $amount) = @_;
my $overdraft_amount = $amount - $self->balance();
if ($self->overdraft_account && $overdraft_amount > 0) {
$self->overdraft_account->withdraw($overdraft_amount);
$self->deposit($overdraft_amount);
}
};
sub withdraw {
my ($self, $amount) = @_;
my $overdraft_amount = $amount - $self->balance();
if ($self->overdraft_account && $overdraft_amount > 0) {
$self->overdraft_account->withdraw($overdraft_amount);
$self->deposit($overdraft_amount);
}
$self->SUPER::withdraw($amount);
}
package Point;
use Moose;
has 'x' => (isa => 'Int', is => 'rw', required => 1);
has 'y' => (isa => 'Int', is => 'rw', required => 1);
sub clear {
my $self = shift;
$self->x(0);
$self->y(0);
}
package Point3D;
use Moose;
extends 'Point';
has 'z' => (isa => 'Int', is => 'rw', required => 1);
after 'clear' => sub {
my $self = shift;
$self->z(0);
};
....
# hash or hashrefs are ok for the constructor
my $point1 = Point->new(x => 5, y => 7);
my $point2 = Point->new({x => 5, y => 7});
my $point3d = Point3D->new(x => 5, y => 42, z => -5);
has 'x' => (isa => 'Int', is => 'rw', required => 1);
sub clear {
my $self = shift;
$self->x(0);
$self->y(0);
}
extends 'Point';
has 'z' => (isa => 'Int', is => 'rw', required => 1);
after 'clear' => sub {
my $self = shift;
$self->z(0);
};
sub clear {
my $self = shift;
$self->SUPER::clear();
$self->z(0);
}
override 'clear' => sub {
my $self = shift;
super();
$self->z(0);
};
my $point1 = Point->new(x => 5, y => 7);
my $point2 = Point->new({x => 5, y => 7});
my $point3d = Point3D->new(x => 5, y => 42, z => -5);
$text = $parent->Text( [ options ... ] )->pack;插入内容
$text->insert('end', "To be or not to be...\nThat is the question");最常见的用法是创建一个Text widget，把从文件读来的内容置于其中$text = $mw->Scrolled("Text")->pack( );
open (FH, "chapter1") || die "Could not open chapter1";
while () {
$text->insert('end', $_);
}
close(FH); $t = $mw->Text()->pack( );添加tag
$t->tagConfigure('bold', -font => "Courier 24 bold");
$t->insert('end', "This is some normal text\n");
$t->insert('end', "This is some bold text\n", 'bold');
1：同时创建widget和scrollbar
$widget = $parent->Scrolled('Widget',
-scrollbars => 'string' [, options ]);
-scrollbar 的值可以是"n", "s", "e", "w"; or "on", "os", "oe", "ow"代表此滚动条出现的方位
Configure
$lb->Subwidget("xscrollbar")->configure(-background => "green");
如果对一个不存在的scrollbar进行配置，则出错
2：单独创建scrollbar
$scrollbar = $mw->Scrollbar([ options ...])
当创建完一个滚动条之后需要和其他widget联系起来
$scrollbar = $mw->Scrollbar( );
$lb = $mw->Listbox(-yscrollcommand => ['set' => $scrollbar]);
#将scrollbar和listbox widget相关联
$scrollbar->configure(-command => ['yview' => $lb]);
#配置点击scrollbar时改变listbox的内容
#Pack the Scrollbar first so that it doesn't disappear when we resize
$scrollbar->pack(-side => 'right', -fill => 'y');
$lb->pack(-side => 'left', -fill => 'both');
scrollbar和其他widget的整合
如前所示，程序通过command选项告诉scrollbar和哪个widget关联，command的值必须是xview或yview，
分别代表scrollbar出现在水平方向和垂直方向的两种情况。
有三种形式的调用
$widget->xviewMoveto(fraction);
$widget->xviewScroll(number, "units");
$widget->xviewScroll(number, "page");
似乎我们并没有必要搞清楚是如何工作的
