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)

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)

不需要花哨的东西:

HTML:

<form method="post" action="/api/admin/image" enctype="multipart/form-data">
    <input type="hidden" name="url" value="<%= boxes[i].url %>" />
    <input class="image-file-chosen" type="text" />
    <br />
    <input class="btn image-file-button" value="Choose Image" />
    <input class="image-file hide" type="file" name="image"/> <!-- Hidden -->
    <br />
    <br />
    <input class="btn" type="submit" name="image" value="Upload" />
    <br />
</form>

JS:

$('.image-file-button').each(function() {
      $(this).off('click').on('click', function() {
           $(this).siblings('.image-file').trigger('click');
      });
});
$('.image-file').each(function() {
      $(this).change(function () {
           $(this).siblings('.image-file-chosen').val(this.files[0].name);
      });
});

注意:所讨论的三个表单元素必须是彼此的兄弟元素(。Image-file-chosen， .image-file-button， .image-file)

不需要额外的插件，这个bootstrap解决方案非常适合我:

<div style="position:relative;">
        <a class='btn btn-primary' href='javascript:;'>
            Choose File...
            <input type="file" style='position:absolute;z-index:2;top:0;left:0;filter: alpha(opacity=0);-ms-filter:"progid:DXImageTransform.Microsoft.Alpha(Opacity=0)";opacity:0;background-color:transparent;color:transparent;' name="file_source" size="40"  onchange='$("#upload-file-info").html($(this).val());'>
        </a>
        &nbsp;
        <span class='label label-info' id="upload-file-info"></span>
</div>

演示:

http://jsfiddle.net/haisumbhatti/cAXFA/1/ (bootstrap 2)

http://jsfiddle.net/haisumbhatti/y3xyU/ (bootstrap 3)

这对我来说非常合适

<span>
    <input  type="file" 
            style="visibility:hidden; width: 1px;" 
            id='${multipartFilePath}' name='${multipartFilePath}'  
            onchange="$(this).parent().find('span').html($(this).val().replace('C:\\fakepath\\', ''))"  /> <!-- Chrome security returns 'C:\fakepath\'  -->
    <input class="btn btn-primary" type="button" value="Upload File.." onclick="$(this).parent().find('input[type=file]').click();"/> <!-- on button click fire the file click event -->
    &nbsp;
    <span  class="badge badge-important" ></span>
</span>

http://markusslima.github.io/bootstrap-filestyle/

$(":file").filestyle();

OR

<input type="file" class="filestyle" data-input="false">