源代码 ：
点击运行
<!DOCTYPE html> <html> <head> <title>Bootstrap 实例</title> <meta charset="utf-8"> <meta name="viewport" content="width=device-width, initial-scale=1"> <link rel="stylesheet" href="https://cdn.staticfile.org/twitter-bootstrap/4.3.1/css/bootstrap.min.css"> <script src="https://cdn.staticfile.org/jquery/3.2.1/jquery.min.js"></script> <script src="https://cdn.staticfile.org/popper.js/1.15.0/umd/popper.min.js"></script> <script src="https://cdn.staticfile.org/twitter-bootstrap/4.3.1/js/bootstrap.min.js"></script> </head> <body> <div class="container"> <button type="button" class="btn btn-secondary" data-toggle="tooltip" data-placement="top" title="Tooltip on top"> Tooltip on top </button> <button type="button" class="btn btn-secondary" data-toggle="tooltip" data-placement="right" title="Tooltip on right"> Tooltip on right </button> <button type="button" class="btn btn-secondary" data-toggle="tooltip" data-placement="bottom" title="Tooltip on bottom"> Tooltip on bottom </button> <button type="button" class="btn btn-secondary" data-toggle="tooltip" data-placement="left" title="Tooltip on left"> Tooltip on left </button> </div> <script> $(document).ready(function(){ $('[data-toggle="tooltip"]').tooltip(); }); </script> </body> </html>
运行结果