Ionicons正在工作，但突然停止了工作，我不知道问题出在哪里，有什么想法吗？我试着取下mr-2的引线，但仍然没有工作。
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css" integrity="sha384-JcKb8q3iqJ61gNV9KGb8thSsNjpSL0n8PARn9HuZOnIxN0hoP+VmmDGMN5t9UJ0Z" crossorigin="anonymous">
<link rel="stylesheet" href="style.css">
<link href="https://fonts.googleapis.com/css?family=Muli:300,700&display=swap" rel="stylesheet">
<div class="d-flex">
<div id="sidebar-container" class="bg-primary">
<div class="menu">
<a href="#" class="d-block text-light p-3"><ion-icon name="radio-button-off-outline lead mr-2"></ion-icon>Singles</a>
<a href="#" class="d-block text-light p-3"><ion-icon name="radio-button-off-outline lead mr-2"></ion-icon>Doubles</a>
<a href="#" class="d-block text-light p-3"><ion-icon name="radio-button-off-outline lead mr-2"></ion-icon>Lower Thirds & Commentators</a>
<a href="#" class="d-block text-light p-3"><ion-icon name="podium-outline lead mr-2"></ion-icon>Bracket Top8</a>
<a href="#" class="d-block text-light p-3"><ion-icon name="trophy-outline lead mr-2"></ion-icon>Results</a>
<a href="#" class="d-block text-light p-3"><ion-icon name="document-text-outline lead mr-2"></ion-icon>Extras</a>
<a href="#" class="d-block text-light p-3"><ion-icon name="cog-outline lead mr-2"></ion-icon>Settings</a>
</div>
</div>
</div>
<script src="https://code.jquery.com/jquery-3.5.1.slim.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/popper.js@1.16.1/dist/umd/popper.min.js"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.5.2/js/bootstrap.min.js"></script>
<script src="https://unpkg.com/ionicons@5.1.2/dist/ionicons.js"></script>您不应该将类名放在(离子图标名称属性(中
这是你的标签：
<ion-icon name="radio-button-off-outline lead mr-2">
这就是解决方案：
<ion-icon name="radio-button-off-outline" class="lead mr-2">
这是一个完整的工作演示：
<!doctype html>
<html lang="en">
<head>
<!-- Required meta tags -->
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<!-- Bootstrap CSS -->
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css" integrity="sha384-JcKb8q3iqJ61gNV9KGb8thSsNjpSL0n8PARn9HuZOnIxN0hoP+VmmDGMN5t9UJ0Z" crossorigin="anonymous">
<link rel="stylesheet" href="style.css">
<link href="https://fonts.googleapis.com/css?family=Muli:300,700&display=swap" rel="stylesheet">
<!-- jQuery always goes to the head section -->
<title>DASHBoard 2.0</title>
</head>
<body>
<div class="d-flex">
<div id="sidebar-container" class="bg-primary">
<div class="menu">
<a href="#" class="d-block text-light p-3"><ion-icon name="radio-button-off-outline" class="lead mr-2"></ion-icon>Singles</a>
<a href="#" class="d-block text-light p-3"><ion-icon name="radio-button-off-outline" class="lead mr-2"></ion-icon>Doubles</a>
<a href="#" class="d-block text-light p-3"><ion-icon name="radio-button-off-outline" class="lead mr-2"></ion-icon>Lower Thirds & Commentators</a>
<a href="#" class="d-block text-light p-3"><ion-icon name="podium-outline" class="lead mr-2"></ion-icon>Bracket Top8</a>
<a href="#" class="d-block text-light p-3"><ion-icon name="trophy-outline" class="lead mr-2"></ion-icon>Results</a>
<a href="#" class="d-block text-light p-3"><ion-icon name="document-text-outline" class="lead mr-2"></ion-icon>Extras</a>
<a href="#" class="d-block text-light p-3"><ion-icon name="cog-outline" class="lead mr-2"></ion-icon>Settings</a>
</div>
</div>
</div>
<!-- Optional JavaScript -->
<!-- jQuery first, then Popper.js, then Bootstrap JS -->
<script src="https://code.jquery.com/jquery-3.5.1.slim.min.js" integrity="sha384-DfXdz2htPH0lsSSs5nCTpuj/zy4C+OGpamoFVy38MVBnE+IbbVYUew+OrCXaRkfj" crossorigin="anonymous"></script>
<script src="https://cdn.jsdelivr.net/npm/popper.js@1.16.1/dist/umd/popper.min.js" integrity="sha384-9/reFTGAW83EW2RDu2S0VKaIzap3H66lZH81PoYlFhbGU+6BZp6G7niu735Sk7lN" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.5.2/js/bootstrap.min.js" integrity="sha384-B4gt1jrGC7Jh4AgTPSdUtOBvfO8shuf57BaghqFfPlYxofvL8/KUEfYiJOMMV+rV" crossorigin="anonymous"></script>
<script src="https://unpkg.com/ionicons@5.1.2/dist/ionicons.js"></script>
</body>
</html>您将引导程序类用于离子图标名称
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css" integrity="sha384-JcKb8q3iqJ61gNV9KGb8thSsNjpSL0n8PARn9HuZOnIxN0hoP+VmmDGMN5t9UJ0Z" crossorigin="anonymous">
<link href="https://fonts.googleapis.com/css?family=Muli:300,700&display=swap" rel="stylesheet">
<script type="module" src="https://unpkg.com/ionicons@5.1.2/dist/ionicons/ionicons.esm.js"></script>
<div class="d-flex">
<div id="sidebar-container" class="bg-primary">
<div class="menu">
<a href="#" class="d-block text-light p-3"><ion-icon name="radio-button-off-outline" class="mr-2 lead"></ion-icon>Singles</a>
<a href="#" class="d-block text-light p-3"><ion-icon name="radio-button-off-outline" class="mr-2 lead"></ion-icon>Doubles</a>
<a href="#" class="d-block text-light p-3"><ion-icon name="radio-button-off-outline" class="mr-2 lead"></ion-icon>Lower Thirds & Commentators</a>
<a href="#" class="d-block text-light p-3"><ion-icon name="radio-button-off-outline" class="mr-2 lead"></ion-icon>Bracket Top8</a>
<a href="#" class="d-block text-light p-3"><ion-icon name="radio-button-off-outline" class="mr-2 lead"></ion-icon>Results</a>
<a href="#" class="d-block text-light p-3"><ion-icon name="radio-button-off-outline" class="mr-2 lead"></ion-icon>Extras</a>
<a href="#" class="d-block text-light p-3"><ion-icon name="radio-button-off-outline" class="mr-2 lead"></ion-icon>Settings</a>
</div>
</div>
</div>
<script src="https://code.jquery.com/jquery-3.5.1.slim.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/popper.js@1.16.1/dist/umd/popper.min.js"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.5.2/js/bootstrap.min.js"></script>