设置上传按钮的样式很麻烦，因为它设置的是输入的样式而不是按钮的样式。

但是你可以用这个技巧:

http://www.quirksmode.org/dom/inputfile.html

简介:

Take a normal <input type="file"> and put it in an element with position: relative. To this same parent element, add a normal <input> and an image, which have the correct styles. Position these elements absolutely, so that they occupy the same place as the <input type="file">. Set the z-index of the <input type="file"> to 2 so that it lies on top of the styled input/image. Finally, set the opacity of the <input type="file"> to 0. The <input type="file"> now becomes effectively invisible, and the styles input/image shines through, but you can still click on the "Browse" button. If the button is positioned on top of the image, the user appears to click on the image and gets the normal file selection window. (Note that you can't use visibility: hidden, because a truly invisible element is unclickable, too, and we need the to remain clickable)

我使用http://gregpike.net/demos/bootstrap-file-input/demo.html:

$('input[type=file]').bootstrapFileInput();

or

$('.file-inputs').bootstrapFileInput();

设置上传按钮的样式很麻烦，因为它设置的是输入的样式而不是按钮的样式。

但是你可以用这个技巧:

http://www.quirksmode.org/dom/inputfile.html

简介:

Take a normal <input type="file"> and put it in an element with position: relative. To this same parent element, add a normal <input> and an image, which have the correct styles. Position these elements absolutely, so that they occupy the same place as the <input type="file">. Set the z-index of the <input type="file"> to 2 so that it lies on top of the styled input/image. Finally, set the opacity of the <input type="file"> to 0. The <input type="file"> now becomes effectively invisible, and the styles input/image shines through, but you can still click on the "Browse" button. If the button is positioned on top of the image, the user appears to click on the image and gets the normal file selection window. (Note that you can't use visibility: hidden, because a truly invisible element is unclickable, too, and we need the to remain clickable)

使用其他答案的部分简化答案，主要是user2309766和dotcomsuperstar。

特点:

为按钮和字段使用引导按钮插件。 只有一个输入;表单将接收多个输入。 除了"display: none;"，没有额外的css来隐藏文件输入。 可见按钮触发隐藏文件输入的单击事件。 分割删除文件路径使用正则表达式和分隔符'\'和'/'。

代码:

<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.4/js/bootstrap.min.js"></script> <link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.4/css/bootstrap.min.css" rel="stylesheet"/> <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <div class="input-group"> <span class="input-group-btn"> <span class="btn btn-primary" onclick="$(this).parent().find('input[type=file]').click();">Browse</span> <input name="uploaded_file" onchange="$(this).parent().parent().find('.form-control').html($(this).val().split(/[\\|/]/).pop());" style="display: none;" type="file"> </span> <span class="form-control"></span> </div>

这是Bootstrap 3,4,5的解决方案。

要制作一个看起来像按钮的功能文件输入控件，你只需要HTML:

HTML

<label class="btn btn-default">
    Browse <input type="file" hidden>
</label>

这适用于所有现代浏览器，包括IE9+。如果你也需要对旧IE的支持，请使用下面所示的遗留方法。

这种技术依赖于HTML5的隐藏属性。Bootstrap 4使用以下CSS在不支持的浏览器中填充此特性。如果使用Bootstrap 3，则可能需要添加。

[hidden] {
  display: none !important;
}

旧IE的遗留方法

如果您需要IE8及以下版本的支持，请使用以下HTML/CSS:

HTML

<span class="btn btn-default btn-file">
    Browse <input type="file">
</span>

CSS

.btn-file {
    position: relative;
    overflow: hidden;
}
.btn-file input[type=file] {
    position: absolute;
    top: 0;
    right: 0;
    min-width: 100%;
    min-height: 100%;
    font-size: 100px;
    text-align: right;
    filter: alpha(opacity=0);
    opacity: 0;
    outline: none;
    background: white;
    cursor: inherit;
    display: block;
}

注意，当你点击<label>时，旧的IE不会触发文件输入，所以CSS“膨胀”做了一些事情来解决这个问题:

使文件输入的跨度为周围<span>的全宽/高 使文件输入不可见

反馈和额外阅读

我已经发布了关于这个方法的更多细节，以及如何向用户显示选中了多少文件的示例:

https://www.abeautifulsite.net/posts/whipping-file-inputs-into-shape-with-bootstrap-3/

这是我喜欢的最好的文件上传风格:

<div class="fileupload fileupload-new" data-provides="fileupload">
  <div class="input-append">
    <div class="uneditable-input span3"><i class="icon-file fileupload-exists"></i> <span class="fileupload-preview"></span></div><span class="btn btn-file"><span class="fileupload-new">Select file</span><span class="fileupload-exists">Change</span><input type="file" /></span><a href="#" class="btn fileupload-exists" data-dismiss="fileupload">Remove</a>
  </div>
</div>

你可以得到演示和更多的风格:

http://www.jasny.net/bootstrap/javascript/#fileinput

但是使用这个，你应该用jasny bootstrap文件替换twitter bootstrap ..

的问候。