方式一：
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>document</title>
<style>
.move {
width: 100px;
height: 100px;
background: red;
border-radius: 50%;
position:absolute;
left:0;
top:0;
}
</style>
</head>
<body>
<div class="move">
</div>
<script>
//制作一个鼠标左键拖拽效果
var div = document.getelementsbyclassname("move")[0];
var style = window.getcomputedstyle(div);
var divleft = parsefloat(style.left);
var divtop = parsefloat(style.top);
div.onmousedown = function(e){
if(e.button !== 0){
return ;//不是鼠标左键，return
}
window.onmousemove = function(e){
divleft += e.movementx;//距上次鼠标位置的x长度
divtop += e.movementy;//距上次鼠标位置的y长度
div.style.left = divleft + "px";
div.style.top = divtop + "px";
}
window.onmouseup = window.onmouseleave = function(){
if(e.button === 0){//鼠标左键
window.onmousemove = null;
}
}
}
</script>
</body>
</html>
方式二：
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>document</title>
<style>
.move {
width: 100px;
height: 100px;
background: red;
border-radius: 50%;
position:absolute;
left:0;
top:0;
}
</style>
</head>
<body>
<div class="move">
</div>
<script>
//制作一个鼠标左键拖拽效果
var div = document.getelementsbyclassname("move")[0];
var style = window.getcomputedstyle(div);
div.onmousedown = function(e){
if(e.button !== 0){
return ;//不是鼠标左键，return
}
var divleft = parsefloat(style.left);
var divtop = parsefloat(style.top);
var divpagex = e.pagex;
var divpagey = e.pagey;
window.onmousemove = function(e){
var disx = e.pagex - divpagex;
var disy = e.pagey - divpagey;
div.style.left = divleft + disx + "px";
div.style.top = divtop + disy + "px";
}
window.onmouseup = window.onmouseleave = function(){
if(e.button === 0){//鼠标左键
window.onmousemove = null;
}
}
}
</script>
</body>
</html>
