按照以下步骤，你就可以为你的文件上传表单创建自定义样式了:

this is the simple HTML form(please read the HTML comments I have written here below) <form action="#type your action here" method="POST" enctype="multipart/form-data"> <div id="yourBtn" style="height: 50px; width: 100px;border: 1px dashed #BBB; cursor:pointer;" onclick="getFile()">Click to upload!</div> <!-- this is your file input tag, so i hide it!--> <div style='height: 0px;width:0px; overflow:hidden;'><input id="upfile" type="file" value="upload"/></div> <!-- here you can have file submit button or you can write a simple script to upload the file automatically--> <input type="submit" value='submit' > </form> then use this simple script to pass the click event to file input tag. function getFile(){ document.getElementById("upfile").click(); } Now you can use any type of styling without worrying about how to change default styles.

我非常清楚这一点，因为我已经尝试更改默认样式一个半月了。相信我，这是非常困难的，因为不同的浏览器有不同的上传输入标签。所以使用这个来构建您的自定义文件上传表单。这里是完整的自动上传代码。

function getFile() { document.getElementById("upfile").click(); } function sub(obj) { var file = obj.value; var fileName = file.split("\\"); document.getElementById("yourBtn").innerHTML = fileName[fileName.length - 1]; document.myForm.submit(); event.preventDefault(); } #yourBtn { position: relative; top: 150px; font-family: calibri; width: 150px; padding: 10px; -webkit-border-radius: 5px; -moz-border-radius: 5px; border: 1px dashed #BBB; text-align: center; background-color: #DDD; cursor: pointer; } <form action="#type your action here" method="POST" enctype="multipart/form-data" name="myForm"> <div id="yourBtn" onclick="getFile()">click to upload a file</div> <!-- this is your file input tag, so i hide it!--> <!-- i used the onchange event to fire the form submission--> <div style='height: 0px;width: 0px; overflow:hidden;'><input id="upfile" type="file" value="upload" onchange="sub(this)" /></div> <!-- here you can have file submit button or you can write a simple script to upload the file automatically--> <!-- <input type="submit" value='submit' > --> </form>

 <label>
    <input type="file" />
 </label>

您可以将input type="file"包装在输入的标签中。样式标签，无论你喜欢和隐藏输入display: none;

我能想到的唯一方法是在它被渲染后用javascript找到按钮，并分配一个样式给它

你也可以看看这个记录

更新没关系，这不能工作在IE或它的新兄弟，FF。可以正常工作在其他类型的元素上，但不能工作在文件输入上。更好的方法是创建一个文件输入和一个链接到它的标签。使文件输入显示无和boom，它在IE9+无缝工作。

警告:以下所有内容都是垃圾!

通过使用根据容器定位/调整大小的伪元素，我们可以只使用一个输入文件(不需要额外的标记)，并按通常的方式设置样式。

Demo

<input type="file" class="foo">
<style>
    .foo {
        display: block;
        position: relative;
        width: 300px;
        margin: auto;
        cursor: pointer;
        border: 0;
        height: 60px;
        border-radius: 5px;
        outline: 0;
    }
    .foo:hover:after {
        background: #5978f8;
    }
    .foo:after {
        transition: 200ms all ease;
        border-bottom: 3px solid rgba(0,0,0,.2);
        background: #3c5ff4;
        text-shadow: 0 2px 0 rgba(0,0,0,.2);
        color: #fff;
        font-size: 20px;
        text-align: center;
        position: absolute;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        display: block;
        content: 'Upload Something';
        line-height: 60px;
        border-radius: 5px;
    }
</style>

享受的家伙!

旧的更新

把这个变成了Stylus mixin。应该很容易让你们中的一个酷SCSS猫转换它。

    file-button(button_width = 150px)
      display block
      position relative
      margin auto
      cursor pointer
      border 0
      height 0
      width 0
      outline none
      &:after
        position absolute
        top 0
        text-align center
        display block
        width button_width
        left -(button_width / 2)

用法:

<input type="file">

input[type="file"]
    file-button(200px)

可见性:隐藏的技巧

我通常会使用可见性:隐藏技巧

这是我设计的按钮

<div id="uploadbutton" class="btn btn-success btn-block">Upload</div>

这是input type=file按钮。注意可见性:隐藏规则

<input type="file" id="upload" style="visibility:hidden;">

这是JavaScript将它们粘合在一起。它的工作原理

<script>
 $('#uploadbutton').click(function(){
    $('input[type=file]').click();
 });
 </script>

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。