参考链接:https://segmentfault.com/a/1190000013606983
例子：
<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8">
<title>菜鸟教程(runoob.com)</title>
<style type="text/css">
#div1 {width:350px;height:70px;padding:10px;border:1px solid #aaaaaa;}
</style>
<script>
function allowDrop(ev)
{
ev.preventDefault();
} function drag(ev)
{
ev.dataTransfer.setData("Text",ev.target.id);
} function drop(ev)
{
ev.preventDefault();
var data=ev.dataTransfer.getData("Text");
ev.target.appendChild(document.getElementById(data));
}
</script>
</head>
<body> <p>拖动 RUNOOB.COM 图片到矩形框中:</p> <div id="div1" ondrop="drop(event)" ondragover="allowDrop(event)"></div>
<br>
<img id="drag1" src="https://www.runoob.com/images/logo.png" draggable="true" ondragstart="drag(event)" width="336" height="69"> </body>
</html>
注意：
drop 是拖放结束的目标区域，要先把dragover的默认事件禁止才能出发drop事件