使用场景

一般用作图形的移动，如svg画图、dom元素的拖拽。。。

测试代码

<!DOCTYPE html>
<html>

<head>
    <meta charset="utf-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <title>Page Title</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link rel="stylesheet" type="text/css" media="screen" href="main.css" />
    <script src="main.js"></script>
    <style>
        body {
            margin: 0px;
            padding: 0px;
            background: black;
        }

        .main {
            width: 500px;
            height: 500px;
            background: yellow;
            display: flex;
            margin: 250px;
            padding: 20px;
        }

        .target {
            box-sizing: border-box;
            margin: 20px;
            padding: 100px;
            width: 100px;
            height: 100px;
            background: red;
        }
    </style>
</head>

<body>
    <div class="div1">
        <div class="main">
            <div class="target"></div>
        </div>
    </div>
</body>
<script>
    var test = document.getElementsByClassName('div1')[0];
    test.onclick = function (e) {
        console.log(e)
    }
</script>

</html>