php无法调用css是因为href为相对路径，其解决办法就是在相对路径中加上STATIC即可，代码语句为“<link rel="stylesheet"href="__STATIC__/bs/css/bootstrap.min.css">”。
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使用php无法引入css问题
href为相对路径加上STATIC可接解决问题
<html>
<head>
<meta charset="UTF-8">
<meta name="viewport"
content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<link rel="stylesheet" href="__STATIC__/bs/css/bootstrap.min.css">
<script src="__STATIC__/bs/js/jquery.min.js"></script>
<script src="__STATIC__/bs/js/bootstrap.min.js"></script>
<title>Document</title>
</head>
<body>
</body>
</html>
浏览器中查看源代码：
| </pre><!doctype html> | | | <html> | | | <head> | | | <meta charset="UTF-8"> | | | <meta name="viewport" | | | content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0"> | | | <meta http-equiv="X-UA-Compatible" content="ie=edge"> | | | <link rel="stylesheet" href="[/tp5/public/static/bs/css/bootstrap.min.css](http://localhost/tp5/public/static/bs/css/bootstrap.min.css)"> | | | <script src="[/tp5/public/static//bs/js/jquery.min.js](http://localhost/tp5/public/static//bs/js/jquery.min.js)"></script> | | | <script src="[/tp5/public/static//bs/js/bootstrap.min.js](http://localhost/tp5/public/static//bs/js/bootstrap.min.js)"></script> | | | <title>Document</title> | | | </head> | | | <body> | | | | | | </body> | | | </html> |