Tk中用Canvas绘图，Scrollbar不起作用_H5之家 - 中国HTML5教程资源分享第一站

use Tk;

use utf8;

$mw = MainWindow->new( );

$mw->geometry("300x100");#1368

$mw->title("模式关系网");#

$mw->title("One Scrollbar/Three Listboxes");

$mw->Button(-text => "Exit",

-command => sub { exit })->pack(-side => 'bottom');

$scltest = $mw->Scrollbar( );

$canvas = $mw->Canvas();

sub scroll_canvas {

my ($scltest, $canvas, @args) = @_;

$scltest->set(@args);

}

$canvas->configure(-yscrollcommand => [ \&scroll_canvas, $scltest,

$canvas, ]);

# Configure the Scrollbar to scroll each Listbox

$scltest->configure(-command => ['yview' => $canvas]);

# Pack the Scrollbar and Listboxes

$scltest->pack(-side => 'left', -fill => 'y');

$canvas->pack(-side => 'left');

my $bt102 = $canvas->Button(-text => "下个方法",

-command => \&printinfo);

my $id102 = $canvas->createWindow(36,30, -window =>$bt102);

my $bt103 = $canvas->Button(-text => "上个方法",

-command => \&printinfo);

my $id104 = $canvas->createWindow(36,200, -window =>$bt104);

my $bt105 = $canvas->createLine( 30,40,400,400, -fill => "green"

);

MainLoop;

sub printinfo

{

print "ok!\n";

}

但是下面的代码是有效的：

use Tk;$mw = MainWindow->new( );

$mw->geometry("200x200");#1368

$mw->title("模式关系网");#

$mw->title("One Scrollbar/Three Listboxes");

$mw->Button(-text => "Exit",

-command => sub { exit })->pack(-side => 'bottom');$scltest = $mw->Scrollbar( );$txt = $mw->Text();# This method is called when one Listbox is scrolled with the keyboard

# It makes the Scrollbar reflect the change, and scrolls the other lists

sub scroll_Text {

my ($scltest, @args) = @_;

$scltest->set(@args); # tell the Scrollbar what to display $lbs,

}

$txt->configure(-yscrollcommand => [ \&scroll_Text, $scltest,

]);$txt,

# Configure the Scrollbar to scroll each Listbox

$scltest->configure(-command => sub {

$txt->yview(@_);

});# Pack the Scrollbar and Listboxes

$scltest->pack(-side => 'left', -fill => 'y');

$txt->pack(-side => 'left');$txt->insert('end', "one", "eight", "nine", "The first argument is the numberof units to scroll by.

The value for number can be any number, but it's typically either 1 or -1. A value of

1 means the next unit of data on the bottom or right of the widget becomes visible

(scrolling one unit of data off the left or top). A value of -1 means that a previous

unit of data will become visible in the top or right of the widget (one unit will scroll

off the bottom or right of the widget). For example, every time the user clicks on the

down arrow in a vertical Scrollbar

associated with a Listbox, a new line shows up at the bottom of the Listbox. ",

"This form is used when the user clicks on the slider,

moves it around, and drops it again. The argument is a fraction, a real number from 0 to 1

that represents the first part of the data to be shown within the widget. If the user moves

the slider all the way to the top or left of the Scrollbar, the very first part of the data

in the widget should be seen on the screen. This means the argument should be 0:");

MainLoop;