<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
<script src="lightbox.js"></script>
</head>
<body>
<div class="test">
<img src="1.jpg" alt="">
<img src="3.jpg" alt="">
</div>
</body>直接调用previewImage方法参数传入需要预览img标签的父元素id或者className或者标签名
<script>
previewImage('.test')
</script>