div拖拽
原理：
鼠标事件
- mousedown
- mousemove
- mouseup
注意事项:
- 被拖动的div的position属性值一定是absolute。
- onmousedown事件需要在window.onload时加载。
- 如果被拖动的div上有文字会有自带的文字拖动效果，需要将改div上的所有拖动事件绑定在该div上，可以使用setCapture。
代码：
html&css：
<!DOCTYPE html>
<html lang="en">
<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="test.js"></script>
<style>
#test {
width: 100px;
height: 100px;
background: #000;
position: absolute;
color: #fff;
}
</style>
</head>
<body>
<div id="test">4616125</div>
</body>
</html>
js
/*
* @Author: lee
* @Date: 2018-07-10 11:40:31
* @Last Modified by: lee
* @Last Modified time: 2018-07-10 16:10:49
*/
(function() {
function Code() {}
Code.prototype = {
addEvent: function() {
var that = this;
var oDiv = document.getElementById('test');
oDiv.onmousedown = function(ev) {
var ev = ev || event;
var distanceX = ev.clientX - this.offsetLeft;
var distanceY = ev.clientY - this.offsetTop;
if (oDiv.setCapture) {
oDiv.setCapture();
}
document.onmousemove = function(ev) {
var ev = ev || event;
oDiv.style.left = ev.clientX - distanceX + 'px';
oDiv.style.top = ev.clientY - distanceY + 'px';
};
document.onmouseup = function(ev) {
document.onmousemove = document.onmouseup = null;
if (oDiv.releaseCapture) {
oDiv.releaseCapture();
}
};
};
},
init: function() {
var that = this;
window.onload = that.addEvent;
},
}
new Code().init();
})();