本文实例为大家分享了JS实现拖拽效果的具体代码，供大家参考，具体内容如下
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
<style type="text/css">
#wrap {
position: relative;
border: 1px solid #000;
width: 800px;
height: 500px;
}
#drog {
position: absolute;
left: 0;
top: 0;
width: 100px;
height: 100px;
background: red;
cursor: move;
}
</style>
</head>
<body>
<div id="wrap">
<div id="drog"></div>
</div>
<script type="text/javascript" src="startmove.js"></script>
<script type="text/javascript">
(function(){
var drog = document.querySelector('#drog');
/*
1.记录按下的时候的鼠标位置
2.记录按下的时候元素的位置
*/
drog.onmousedown = function(e){
var startElY = css(drog,"top");
var startElX = css(drog,"left");
var startMouseX = e.clientX;
var startMouseY = e.clientY;
/*
求出鼠标移动的距离，
操作元素也移动相应的距离
为了可以一直跟随，所以添加给document
*/
document.onmousemove = function(e){
var nowMouseX = e.clientX;
var nowMouseY = e.clientY;
var disX = nowMouseX - startMouseX;
var disY = nowMouseY - startMouseY;
var x = disX + startElX;
var y = disY + startElY;
css(drog,"left",x);
css(drog,"top",y);
};
document.onmouseup = function(){
document.onmousemove = null;
document.onmouseup = null;
};
};
})();
</script>
</body>
</html>
