我从this Codepen复制了此代码。但是，即使我在所需的Javascript中进行链接，在控制台中也可以看到“未定义mdc”错误。我在哪里出错了？
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width,initial-scale=1,shrink-to-fit=no">
<link href="https://fonts.googleapis.com/css?family=Roboto+Mono" rel="stylesheet">
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/normalize/8.0.0/normalize.min.css">
<link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Roboto:300,400,500,700">
<link rel="stylesheet" href="https://unpkg.com/material-components-web@latest/dist/material-components-web.min.css">
<link rel="stylesheet" href="https://fonts.googleapis.com/icon?family=Material+Icons">
<link rel="stylesheet" href="./test.css">
<script>src="https://unpkg.com/material-components-web@latest/dist/material-components-web.min.js"</script>
<script>
// Instantiate MDC Drawer
const drawerEl = document.querySelector('.mdc-drawer');
const drawer = new mdc.drawer.MDCDrawer.attachTo(drawerEl);
// Instantiate MDC Top App Bar (required)
const topAppBarEl = document.querySelector('.mdc-top-app-bar');
const topAppBar = new mdc.topAppBar.MDCTopAppBar.attachTo(topAppBarEl);
topAppBar.setScrollTarget(document.querySelector('.main-content'));
topAppBar.listen('MDCTopAppBar:nav', () => {
drawer.open = !drawer.open;
});
</script>
</head>
<body>
<!-- Top App Bar -->
<header class="mdc-top-app-bar">
<div class="mdc-top-app-bar__row">
<section class="mdc-top-app-bar__section mdc-top-app-bar__section--align-start">
<button class="mdc-top-app-bar__navigation-icon mdc-icon-button material-icons" href="#">menu</button>
<a class="mdc-top-app-bar__title" href="https://www.webdenim.io" target="_blank" style="color: inherit;">Webdenim</a>
</section>
</div>
</header>
<div class="app-drawer-layout mdc-top-app-bar--fixed-adjust">
<!-- Drawer -->
<aside class="mdc-drawer mdc-drawer--dismissible demo-drawer">
<nav class="mdc-drawer__drawer">
<nav class="mdc-drawer__content">
<div id="icon-with-text-demo" class="mdc-list">
<a class="mdc-list-item mdc-list-item--selected demo-drawer-list-item" href="#">
<i class="material-icons mdc-list-item__graphic" aria-hidden="true">inbox</i>Inbox
</a>
<a class="mdc-list-item demo-drawer-list-item" href="#">
<i class="material-icons mdc-list-item__graphic" aria-hidden="true">star</i>Star
</a>
<a class="mdc-list-item demo-drawer-list-item" href="#">
<i class="material-icons mdc-list-item__graphic" aria-hidden="true">send</i>Sent Mail
</a>
<a class="mdc-list-item demo-drawer-list-item" href="#">
<i class="material-icons mdc-list-item__graphic" aria-hidden="true">drafts</i>Drafts
</a>
</div>
<hr class="mdc-list-divider">
<div class="mdc-list">
<a class="mdc-list-item demo-drawer-list-item" href="#">
<i class="material-icons mdc-list-item__graphic" aria-hidden="true">email</i>All Mail
</a>
<a class="mdc-list-item demo-drawer-list-item" href="#">
<i class="material-icons mdc-list-item__graphic" aria-hidden="true">delete</i>Trash
</a>
<a class="mdc-list-item demo-drawer-list-item" href="#">
<i class="material-icons mdc-list-item__graphic" aria-hidden="true">report</i>Spam
</a>
</div>
</nav>
</nav>
</aside>
<!-- Content -->
<main class="mdc-drawer-app-content main-content">
<div class="demo-image">
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</div>
<div class="demo__title">Click the menu button</div>
<div class="demo__subtitle"> at the top left of the page to toggle the drawer</div>
</main>
</div>
</body>
</html>
答案 0 :(得分：2)
脚本注入有问题
<script>src="https://unpkg.com/material-components-web@latest/dist/material-components-web.min.js"</script>
应该是
<script src="https://unpkg.com/material-components-web@latest/dist/material-components-web.min.js"></script>