perl - 在文本小部件中打印行号

Question

我使用以下代码在 Text 小部件中打印行号:

my $c = 0;
my $r = 0;

$txt = $mw->Text(
    -background          => 'white',
    -width               => 400,
    -height              => 300,
    -selectbackground    => 'skyblue',
    -insertwidth         => 5,
    -borderwidth         => 3,
    -highlightcolor      => 'blue',  # after visit
    -highlightbackground => 'red',   # default before visit
    -xscrollcommand      => sub { print "CHAT NO :", $c++; },
    # Determines the callback used when the Text widget is scrolled horizontally.
    -yscrollcommand      => sub { print "LINR NO:", $r++; },
    # Determines the callback used when the Text widget is scrolled vertically.
    -padx                => 5,
    -pady                => 5,
)->pack();

上面的代码可以打印行号和字符号，但是在 Scrolled 小部件中使用时，输出不打印。下面的代码有什么问题？我该如何解决这个问题？

$txt = $mw->Scrolled('Text',
    -scrollbars          => 'se',
    -background          =>'white',
    -width               => 400,
    -height              => 300,
    -insertwidth         => 5,
    -borderwidth         =>3,
    -highlightcolor      => 'blue',  # after visit
    -highlightbackground => 'red' ,  # default before visit
    -padx                => 5,
    -pady                => 5,
    # Determines the callback used when the Text widget is scrolled horizontally. 
    -xscrollcommand      => sub { print"CHAT NO :",$c++; },
    # Determines the callback used when the Text widget is scrolled vertically.
    -yscrollcommand      => sub { print"LINR NO :",$r++; },
)->pack();

Answer 1

Scrolled megawidget 自动创建滚动条绑定(bind)。它正在设置 -xscrollcommand和 -yscrollcommand绑定(bind)，它会覆盖您在创建小部件时指定的绑定(bind)。如果你想[ab]使用滚动命令来输出行号/列号，你必须放弃使用Scrolled。并自己创建滚动条和绑定(bind)。