Question

为什么我收到控制台错误＆＃34; Uncaught TypeError：无法设置属性＆＃39; ondragover＆＃39; of null＆＃34;

<html>
  <head>
    <title></title>
    <script>

    var dragzone = document.getElementById('DragZone');

    dragzone.ondragover=function() {
        console.log("Bang");
        return false;
    };

    </script>

 </head>

<body>
    <div id="DragZone">Drag a file over here</div>
</body>
</html>

Answer 1

您正在尝试在创建DOM元素之前访问它。将脚本移动到<body>的底部，它将起作用。

<html>
<head>
    <title></title>
</head>
<body>
    <div id="DragZone">Drag a file over here</div>
    <script>
        var dragzone = document.getElementById('DragZone');
        dragzone.ondragover=function() {
            console.log("Bang");
            return false;
        };
    </script>
</body>
</html>

JavaScript＆＃39; ondragover＆＃39;导致控制台错误，为什么？

1 个答案: