效果如下:

 

 


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
<!DOCTYPE html>
<html>
<head>
    <title></title>
    <style type="text/css">
        body{position:relative;}
        *{padding:0;margin:0;}
        .dialog{width:400px;height:400px;border:1px solid #ddd;position:fixed;top:100px;left:200px;}
        .dialog h2{height:40px;background:purple;cursor:move;}
        .mask{position:fixed;width:0;height:0;left:0;top:0;display:none;border: 3px solid #eee;box-shadow: 0px 0px 10px 5px rgba(0, 0, 0, 0.07);cursor:move;}
    </style>
</head>
<body>
    <div class="dialog" id="box">
        <h2 id='digTit'></h2>
    </div>
    <div class="mask"></div>
    <script type="text/javascript">
        var dragEle = document.getElementById('digTit')
        var box = document.getElementById('box')
        var x,y // 物体离上边,下边的距离
        var moveBox = document.querySelector('.mask') // 移动的是这层
        // 设置居中
        var oldX = (document.documentElement.clientWidth-box.offsetWidth)/2
        var oldY = (document.documentElement.clientHeight-box.offsetHeight)/2
        box.style.left = oldX + 'px'
        box.style.top = oldY + 'px'
        moveBox.style.left = oldX + 'px'
        moveBox.style.top = oldY + 'px'
        moveBox.style.width = box.offsetWidth + 'px'
        moveBox.style.height = box.offsetHeight + 'px'
                 
 
        digTit.addEventListener('mousedown', function (e) {
            moveBox.style.display = 'block'
            var beginX = e.clientX
            var beginY = e.clientY
 
            document.addEventListener('mousemove', move, false)
            document.addEventListener('mouseup', up, false)
 
            function move(e) {
                x = oldX + e.clientX - beginX
                y = oldY + e.clientY - beginY
                moveBox.style.left = x + 'px'
                moveBox.style.top = y + 'px'
            }
 
            function up(e) {
                box.style.left = x + 'px'
                box.style.top = y + 'px'
                oldX = x
                oldY = y
                moveBox.style.display = 'none'
                document.removeEventListener('mousemove', move, false)
                document.removeEventListener('mouseup', up, false)
            }
        }, false)
    </script>
</body>
</html>