你不需要JavaScript !下面是一个跨浏览器的解决方案:

请看这个例子!-适用于Chrome/FF/IE - (IE10/9/8/7)

最好的方法是将一个带有for属性的自定义标签元素附加到隐藏的文件输入元素。(标签的for属性必须匹配文件元素的id，这样才能工作)。

<label for="file-upload" class="custom-file-upload">
    Custom Upload
</label>
<input id="file-upload" type="file"/>

作为一种替代方法，你也可以直接用标签包装文件输入元素:

<label class="custom-file-upload">
    <input type="file"/>
    Custom Upload
</label>

在样式方面，只需使用属性选择器隐藏输入元素。

input[type="file"] {
    display: none;
}

然后，您所需要做的就是设置自定义标签元素的样式。(例子)。

.custom-file-upload {
    border: 1px solid #ccc;
    display: inline-block;
    padding: 6px 12px;
    cursor: pointer;
}

1 -值得注意的是，如果你使用display: none隐藏元素，它将在IE8及以下版本中不起作用。还要注意，jQuery验证默认情况下不验证隐藏字段。如果这两种情况对您来说是一个问题，这里有两种不同的方法来隐藏输入(1,2)，在这种情况下可以工作。

这是一个纯CSS，无javascript，无bootstrap, 100%跨浏览器的解决方案!只需剪切粘贴一个样式块，然后测试您的文件上传控制。

这个解决方案不像其他文章那样试图隐藏然后重新创建原始HTML元素。它使用纯CSS，没有任何马戏团技巧或第三方工具，为所有主要浏览器设置原始文件上传表单控件的样式。你甚至不需要改变你的HTML代码!只需剪切并粘贴下面的代码到你的网页来测试它…

<style>
/* Note: This CSS will style all instances of 
   <input type=file /> controls in your website. */
input[type="file"],
input[type="file"]:visited,
input[type="file"]:hover,
input[type="file"]:focus,
input[type="file"]:active {
    margin:0;
    padding: 0em 0em;/* fallback: older browsers like IE 1-8 need "em" */
    padding: 0rem 0rem;/* older browsers dont know what "rem" is */
    overflow: hidden; /* long file names overflow so just hide the end */
    background: #fff;
    border-radius: .2em;
    border-radius: .2rem;
    outline: none;
    border: 2px solid #bbb;
    cursor: pointer;
    -webkit-appearance: textfield;
    -moz-appearance: textfield;
}

input[type="file"]:hover {
    background: #f9f9ff; /* Optional rollover color: I am using a light blue to indicate an interaction */
    border: 2px solid #999;
}

input[type="file"]:visited,
input[type="file"]:focus,
input[type="file"]:active {
    background: #fff; /* Default back to white when focused. */
    border: 2px solid #999;
}

/* Note: These "disabled" selectors blow up in IE so have to be separated from the same styles above. */
input[type="file"]:disabled {
    margin: 0;
    padding: 0em 0em;
    padding: 0rem 0rem;
    overflow: hidden; /* long file names overflow so just hide the end */
    background: #ddd;
    border-radius: .2em;
    border-radius: .2rem;
    outline: none;
    border: 2px solid #bbb;
    cursor: pointer;
    -webkit-appearance: textfield;
    -moz-appearance: textfield;
}

input[type="file"]:disabled:hover {
    background: #ddd; /* disabled-readonly buttons should be grey */
    border: 2px solid #999;
}

input[type="file"]:disabled:visited,
input[type="file"]:disabled:focus,
input[type="file"]:disabled:active {
    background: #ddd; /* disabled-readonly buttons should be grey */
    border: 2px solid #999;
}

/* IE UPLOAD BUTTON STYLE: This attempts to alter the file upload button style in IE.  Keep in mind IE gives you limited design control but at least you can customize its upload button.*/
::-ms-browse { /* IE */
    display: inline-block;
    margin: 0;
    padding: .2em .5em;
    padding: .2rem .5rem;
    text-align: center;
    outline: none;
    border: none;
    background: #fff;
    white-space: nowrap;
    cursor: pointer;
}
/* FIREFOX UPLOAD BUTTON STYLE */
::file-selector-button {/* firefox */
    display: inline-block;
    margin: 0rem 1rem 0rem 0rem;
    padding: .18em .5em;
    padding: .18rem .5rem;
    -webkit-appearance: button;
    text-align: center;
    border-radius: .1rem 0rem 0rem .1rem;
    outline: none;
    border: none;
    border-right: 2px solid #bbb;
    background: #eee;
    white-space: nowrap;
    cursor: pointer;
}
/* CHROME AND EDGE UPLOAD BUTTON STYLE */
::-webkit-file-upload-button { /* chrome and edge */
    display: inline-block;
    margin: 0rem 1rem 0rem 0rem;
    padding: .19em .5em;
    padding: .19rem .5rem;
    -webkit-appearance: button;
    text-align: center;
    border-radius: .1rem 0rem 0rem .1rem;
    outline: none;
    border: none;
    border-right: 2px solid #bbb;
    background: #eee;
    white-space: nowrap;
    cursor: pointer;
}
</style>

<input type="file" id="fileupload" name="fileupload" 
value="" tabindex="0" enctype="multipart/form-data" 
accept="image/*" autocomplete="off" multiple="multiple" 
aria-multiselectable="true" title="Multiple File Upload" 
aria-label="Multiple File Upload" />

<br /><br />

<input disabled="disabled" type="file" id="fileupload" 
name="fileupload" value="" tabindex="0" 
enctype="multipart/form-data" accept="image/*" 
autocomplete="off" multiple="multiple" 
aria-multiselectable="true" title="Disabled Multiple File Upload" 
aria-label="Disabled Multiple File Upload" />

这是文件上传控件在Firefox、Chrome和Edge中使用下面的CSS的样子。这是一个非常简单干净的设计。你可以把它变成你喜欢的样子:

Internet Explorer为您提供了有限的设计控制，但至少您可以使用CSS操作控件来更改一些东西，包括圆形边框和颜色:

我的解决方案的优点是:

You stick with simple CSS to style the original HTML input control You can see one or more file names in the file input textbox Screen readers and ARIA-friendly devices can interact normally with your file upload control You can set tabindex on your HTML element so its part of the tab order Because you are using plain HTML and CSS, your file input button works perfectly in old and new browsers ZERO JavaScript required! Runs and loads lighting fast in even the oldest of browsers Because your are not using "display:none" to hide the control, its file block stream data is never disabled from reaching the server in any old or new browser version known

你不需要愚蠢的JavaScript技巧，Bootstrap，或尝试隐藏/重新创建你的文件输入控件。这只会破坏所有在线用户的可用性。样式化原始HTML控件意味着你的文件上传控件在25年的新老浏览器中都能很好地工作。

This is why you cannot trust all these scripted hacks here that erase, rewrite, or destroy HTML just to try and recreate some visual experience. That shows that you do not understand how HTML is used or why its been around for 30 years practically unchanged. You should never try and rewrite HTML's native form control functionality. Why? There is more to using natural HTML in websites than just manipulation of markup for some forced visual experience. The trade-offs of limited visual design in these replaced HTML elements was designed that way for a reason.

我的建议是:坚持使用简单的HTML和CSS解决方案，作为web开发人员，你将没有任何问题。

这里有一个交叉兼容的方法，可以在Chrome, Firefox, Safari和IE中工作。

$(window).on('resize',function() { var eqw = $('input[type=text]').width(); $('textarea').width(eqw - 32); $('.fileoutline').width(eqw); }).trigger('resize'); $('.file+.file').hide(); $(".file").click(function() { var input = $(this).next().find('input'); input.click(); }); $("input[id='file1']").change(function () { $('.file+.file').show(); var filename = $(this).val(); $('.filename1').html(filename); $('.file').find('span').html('CHANGE FILE'); }); $("input[id='file2']").change(function() { var filename = $(this).val(); $('.filename2').html(filename); $('.file').find('span').html('CHANGE FILE'); }); form { width:55%;margin:0 auto;padding-left:3vw;text-align:left; } fieldset{border:0;margin:0;padding:0;} textarea{overflow: auto;height:25vh;resize:none;outline:none;width:93%;background:none;padding:8px 15px;display:block;text-align:left;border:1px solid #000;margin:0;color:#000;font:700 0.85em/2.2 'Futura Book',Arial,sans-serif;} input:focus{outline:none;} input[type=text]{font-weight:700;font-size:0.85em;line-height:2.2;background:none;text-align:left;letter-spacing:0.02em;height:33px;display:block;width:100%;border:none;border-bottom:1px solid #000;margin:0 0 28px;color:#000;} input:focus{outline:0;} .fileoutline { width:100%;margin:25px auto 0px;left:0;right:0;height:40px;border:1px solid #000;position:relative; } input[type=file] { -webkit-appearance: none;-moz-appearance:none;appearance: none;opacity:0;position:relative;width:100%;height:35px;font-weight:700;font-size:0.5em;line-height:28px;letter-spacing:0.2em;position: absolute;left: 0;top: 0;height: 100%;z-index:10; } .file,.filename1,.filename2,#submit { font-size:10px;letter-spacing:0.02em;text-transform:uppercase;color:#ffffff;text-align:center;width:35%;} .file,.filename1,.filename2 { font-weight:200;line-height:28px;} .filename1,.filename2 { width:375px;overflow:hidden;top:0;text-align:right;position:absolute;display:block;height:26px;color:#000;} .file { position:absolute;width:100px;top:6px;left:10px;background:#000;border-radius:14px; } ::-webkit-file-upload-button,::-ms-browse { width: 100%;height:25px;opacity: 0;-webkit-appearance: none;appearance: none; } #submit{border:none;height:32px;background: #000;box-shadow:0 0 0 0.5px #fff,0 0 0 5px #000;margin:35px 0;float:right;display:block;} <form action="" method="post" enctype="multipart/form-data"> <input type="text" name="email" id="email" placeholder="Email address" /> <input type="text" type="text" name="name" id="title" placeholder="Name" /> <textarea rows="7" cols="40" name="description" id="description" placeholder="Description"></textarea> <div class="fileoutline"><div class="file"><span>CHOOSE FILE</span><input type="file" name="file[]" id="file1"><div class="filename1">NO CHOSEN FILE</div></div></div> <div class="fileoutline"><div class="file"><span>CHOOSE FILE</span><input type="file" name="file[]" id="file2"><div class="filename2">NO CHOSEN FILE</div></div></div> <input type="submit" name="submit" value="Submit" id="submit"> </form>

这些答案很好，它们都适用于非常具体的用例。也就是说，他们固执己见。

所以，这里有一个答案，它没有任何假设，但无论你如何修改它都是有效的。你可以用css改变设计，添加javascript，可能会显示一个文件名的变化，等等，它仍然会一直工作。

代码:

这里是核心css

.file-input{
  pointer-events: none;
  position: relative;
  overflow: hidden;
}
.file-input > * {
  pointer-events: none;
}
.file-input > input[type="file"]{
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  opacity: 0;
  pointer-events: all;
  cursor: pointer;
  height: 100%;
  width: 100%;
}

和核心html:

<div class="file-input">
  <input type="file"/>
</div>

如您所见，我们强制将.file-input元素或其任何子元素上发生的任何指针事件(单击)代理到文件输入。这是因为文件输入的位置是绝对的，并且总是占用容器的宽度/高度。因此，您可以根据自己的需要进行定制。样式包装成一个按钮，使用一些js显示文件名选择，等等，没有什么会打破，只要上述核心代码保持不变。

正如你将在演示中看到的，我已经添加了一个带有文本“Select file”的span和一个带有额外样式的类来设置.file-input div的样式。这应该是任何人想要创建自定义文件上传元素的规范起点。

演示：JSFIDDLE

CSS在这里可以做很多事情…耍点小花招……

<div id='wrapper'>
    <input type='file' id='browse'>
</div>
<style>
    #wrapper {
            width: 93px; /*play with this value */
            height: 28px; /*play with this value */
            background: url('browseBtn.png') 0 0 no-repeat;
            border:none;
            overflow:hidden;
    }

    #browse{
            margin-left:-145px; /*play with this value */
            opacity:0; /* set to .5 or something so you can better position it as an overlay then back to zero again after you're done */
            -ms-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=0)";
            filter: progid:DXImageTransform.Microsoft.Alpha(Opacity=0);
    }
</style>

::参考::http://site-o-matic.net/?viewpost=19

修道院

把上传文件按钮放在你漂亮的按钮或元素上并隐藏它。

非常简单，可以在任何浏览器上工作

<div class="upload-wrap">
    <button type="button" class="nice-button">upload_file</button>
    <input type="file" name="file" class="upload-btn">
</div>

风格

.upload-wrap {
    position: relative;
}

.upload-btn {
    position: absolute;
    left: 0;
    opacity: 0;
}