我的班级出现以下错误：“无法在file.do第26行修改非左值子程序调用.”我的file.do看起来像这样：
line 2: use BookController; line 3: my $bookdb = BookController->new(); ... line 26: $bookdb->dbh = 0;
我的BookController.pm看起来像这样：
#!/usr/bin/perl
package BookController;
use strict;
sub new
{
my $this = shift;
my $class = ref($this) || $this;
my $self = {};
$self->{DBH} = undef;
bless $self,$class;
return ($self);
}
sub dbh
{
my $self = shift;
$self->{DBH} = shift if (@_);
return $self->{DBH};
}
1;
有什么建议？