利用样式覆盖来实现效果：先看下原本和改变后的样式
1 <!doctype html>
2 <html>
3 <head>
4 <title>file自定义上传样式</title>
5 <style>
6 *
7 {
8 margin: 0;
9 padding: 0;
10 }
11 /*蓝色按钮,绝对定位*/
12 .btn
13 {
14 position: absolute;
15 width: 100px;
16 height: 40px;
17 background-color: #2db7f5;
18 color: #fff;
19 text-align: center;
20 font-weight: 900;
21 border-radius: 4px;
22 }
23 /*自定义上传,位置大小都和btn完全一样,而且完全透明*/
24 .file-upload
25 {
26 position: absolute;
27 display: block;
28 width: 100px;
29 height: 40px;
30 opacity: 0;
31 cursor: pointer;
32 }
33 .file-name
34 {
35 position: absolute;
36 top:40px;
37 width: 100%;
38 height: 30px;
39 }
40 </style>
41 </head>
42 <body>
43 <button class="btn">上传文件</button>
44 <input type="file" class="file-upload" />
45 <div class="file-name"></div>
46 </body>
47 </html>
48 <script src="https://cdn.bootcss.com/jquery/3.3.1/jquery.min.js"></script>
49 <script>
50 $(document).ready(function()
51 {
52 $(".file-upload").change(function()
53 {
54 var arrs=$(this).val().split('\\');
55 var filename=arrs[arrs.length-1];
56 $(".file-name").html(filename);
57 });
58 });
59 </script>
