<html>
<head>
<style>
.droptarget {
float: left;
width: 100px;
height: 35px;
margin: 15px;
margin-right: 100px;
padding: 10px;
border: 1px solid #aaaaaa;
}
</style>
</head>
<body>
<p>在两个矩形框中来回拖动 p 元素:</p>
<div class="droptarget" ondrop="drop(event)" ondragenter="dragEnter(event)" ondragleave="dragLeave(event)" ondragover="allowDrop(event)">
<p ondragstart="dragStart(event)" draggable="true" id="dragtarget">拖动我!</p>
</div>
<div class="droptarget" ondragenter="dragEnter(event)" ondragleave="dragLeave(event)" ondrop="drop(event)" ondragover="allowDrop(event)"></div>
<p style="clear:both;"><strong>注意：</strong>Internet Explorer 8 及更早 IE 版本或 Safari 5.1 及更早版本的浏览器不支持 drag 事件。</p>
<p id="demo"></p>
<script>
function dragStart(event) {
event.dataTransfer.setData("Text", event.target.id);
}
function dragEnter(event) {
document.getElementById("demo").innerHTML = "进入放置区域";
if ( event.target.className == "droptarget" ) {
event.target.style.border = "3px dotted red";
}
}
function dragLeave(event) {
document.getElementById("demo").innerHTML = "离开放置区域";
if ( event.target.className == "droptarget" ) {
event.target.style.border = "";
}
}
function allowDrop(event) {
event.preventDefault();
}
function drop(event) {
event.preventDefault();
var data = event.dataTransfer.getData("Text");
event.target.appendChild(document.getElementById(data));
}
</script>
</body>
</html>