样式化文件上传“浏览”按钮

Question

我有一个使用Bootstrap 的asp.net 网站，并且在一个页面上我有一个文件上传字段。现在我知道这已经被问过很多次了，但我似乎无法为 asp.net 找到解决方案。

理想情况下，我所追求的是设置文件上传“浏览”按钮的样式，因此它只是一个文件字形图标，因此查看 Bootstrap 站点我想使用类似的东西

我想要的样子（取自 Bootstrap 网站）

<div class="input-group">
     <input type="text" class="form-control" placeholder="Username" aria-describedby="basic-addon1">
     <span class="input-group-addon" id="basic-addon1">
          <i class="glyphicon glyphicon-folder-open"></i>
     </span>
</div>

所以我会在 input 字段的末尾加上文件夹图标，但我似乎找不到这样做的方法，想知道是否有其他人可以提供帮助。

我当前的代码是：

<div class="form-group">
     <asp:Label ID="Label3" class="col-md-3 control-label" runat="server" Text="Upload"></asp:Label>
     <div class="col-md-3">
          <asp:FileUpload ID="fuAttachment" runat="server" class="fileupload"></asp:FileUpload>
     </div>
</div>

我的自定义 CSS 是

.fileupload
{
    font-family: inherit;
    font-size: inherit;
    line-height: inherit;
    width: 100%;
    height: 32px;    
    pointer-events: none;
}

Answer 1

html

<div class="upload">
    <input type="file" name="upload"/>
</div>

css

div.upload {
   width: 157px;
   height: 57px;
   background: #ccc;
   overflow: hidden;
}

div.upload input {
    display: block;
    width: 157px;
    height: 57px;
    opacity: 0;
    overflow: hidden;
}

Answer 2

你可以这样尝试：Demo

使用 Bootstrap 按钮来设置上传按钮的样式。

.fileUpload {
    position: relative;
    overflow: hidden;
    margin: 10px;
}
.fileUpload input.upload {
    position: absolute;
    top: 0;
    right: 0;
    margin: 0;
    padding: 0;
    font-size: 20px;
    cursor: pointer;
    opacity: 0;
    filter: alpha(opacity=0);
}

Answer 3

Jasny Plugin这个插件可能会有所帮助。

/* ===========================================================
 * Bootstrap: fileinput.js v3.1.3
 * http://jasny.github.com/bootstrap/javascript/#fileinput
 * ===========================================================
 * Copyright 2012-2014 Arnold Daniels
 *
 * Licensed under the Apache License, Version 2.0 (the "License")
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * ========================================================== */

+ function($) {
  "use strict";

  var isIE = window.navigator.appName == 'Microsoft Internet Explorer'

  // FILEUPLOAD PUBLIC CLASS DEFINITION
  // =================================

  var Fileinput = function(element, options) {
    this.$element = $(element)

    this.$input = this.$element.find(':file')
    if (this.$input.length === 0) return

    this.name = this.$input.attr('name') || options.name

    this.$hidden = this.$element.find('input[type=hidden][name="' + this.name + '"]')
    if (this.$hidden.length === 0) {
      this.$hidden = $('<input type="hidden">').insertBefore(this.$input)
    }

    this.$preview = this.$element.find('.fileinput-preview')
    var height = this.$preview.css('height')
    if (this.$preview.css('display') !== 'inline' && height !== '0px' && height !== 'none') {
      this.$preview.css('line-height', height)
    }

    this.original = {
      exists: this.$element.hasClass('fileinput-exists'),
      preview: this.$preview.html(),
      hiddenVal: this.$hidden.val()
    }

    this.listen()
  }

  Fileinput.prototype.listen = function() {
      this.$input.on('change.bs.fileinput', $.proxy(this.change, this))
      $(this.$input[0].form).on('reset.bs.fileinput', $.proxy(this.reset, this))

      this.$element.find('[data-trigger="fileinput"]').on('click.bs.fileinput', $.proxy(this.trigger, this))
      this.$element.find('[data-dismiss="fileinput"]').on('click.bs.fileinput', $.proxy(this.clear, this))
    },

    Fileinput.prototype.change = function(e) {
      var files = e.target.files === undefined ? (e.target && e.target.value ? [{
        name: e.target.value.replace(/^.+\\/, '')
      }] : []) : e.target.files

      e.stopPropagation()

      if (files.length === 0) {
        this.clear()
        return
      }

      this.$hidden.val('')
      this.$hidden.attr('name', '')
      this.$input.attr('name', this.name)

      var file = files[0]

      if (this.$preview.length > 0 && (typeof file.type !== "undefined" ? file.type.match(/^image\/(gif|png|jpeg)$/) : file.name.match(/\.(gif|png|jpe?g)$/i)) && typeof FileReader !== "undefined") {
        var reader = new FileReader()
        var preview = this.$preview
        var element = this.$element

        reader.onload = function(re) {
          var $img = $('<img>')
          $img[0].src = re.target.result
          files[0].result = re.target.result

          element.find('.fileinput-filename').text(file.name)

          // if parent has max-height, using `(max-)height: 100%` on child doesn't take padding and border into account
          if (preview.css('max-height') != 'none') $img.css('max-height', parseInt(preview.css('max-height'), 10) - parseInt(preview.css('padding-top'), 10) - parseInt(preview.css('padding-bottom'), 10) - parseInt(preview.css('border-top'), 10) - parseInt(preview.css('border-bottom'), 10))

          preview.html($img)
          element.addClass('fileinput-exists').removeClass('fileinput-new')

          element.trigger('change.bs.fileinput', files)
        }

        reader.readAsDataURL(file)
      } else {
        this.$element.find('.fileinput-filename').text(file.name)
        this.$preview.text(file.name)

        this.$element.addClass('fileinput-exists').removeClass('fileinput-new')

        this.$element.trigger('change.bs.fileinput')
      }
    },

    Fileinput.prototype.clear = function(e) {
      if (e) e.preventDefault()

      this.$hidden.val('')
      this.$hidden.attr('name', this.name)
      this.$input.attr('name', '')

      //ie8+ doesn't support changing the value of input with type=file so clone instead
      if (isIE) {
        var inputClone = this.$input.clone(true);
        this.$input.after(inputClone);
        this.$input.remove();
        this.$input = inputClone;
      } else {
        this.$input.val('')
      }

      this.$preview.html('')
      this.$element.find('.fileinput-filename').text('')
      this.$element.addClass('fileinput-new').removeClass('fileinput-exists')

      if (e !== undefined) {
        this.$input.trigger('change')
        this.$element.trigger('clear.bs.fileinput')
      }
    },

    Fileinput.prototype.reset = function() {
      this.clear()

      this.$hidden.val(this.original.hiddenVal)
      this.$preview.html(this.original.preview)
      this.$element.find('.fileinput-filename').text('')

      if (this.original.exists) this.$element.addClass('fileinput-exists').removeClass('fileinput-new')
      else this.$element.addClass('fileinput-new').removeClass('fileinput-exists')

      this.$element.trigger('reset.bs.fileinput')
    },

    Fileinput.prototype.trigger = function(e) {
      this.$input.trigger('click')
      e.preventDefault()
    }


  // FILEUPLOAD PLUGIN DEFINITION
  // ===========================

  var old = $.fn.fileinput

  $.fn.fileinput = function(options) {
    return this.each(function() {
      var $this = $(this),
        data = $this.data('bs.fileinput')
      if (!data) $this.data('bs.fileinput', (data = new Fileinput(this, options)))
      if (typeof options == 'string') data[options]()
    })
  }

  $.fn.fileinput.Constructor = Fileinput


  // FILEINPUT NO CONFLICT
  // ====================

  $.fn.fileinput.noConflict = function() {
    $.fn.fileinput = old
    return this
  }


  // FILEUPLOAD DATA-API
  // ==================

  $(document).on('click.fileinput.data-api', '[data-provides="fileinput"]', function(e) {
    var $this = $(this)
    if ($this.data('bs.fileinput')) return
    $this.fileinput($this.data())

    var $target = $(e.target).closest('[data-dismiss="fileinput"],[data-trigger="fileinput"]');
    if ($target.length > 0) {
      e.preventDefault()
      $target.trigger('click.bs.fileinput')
    }
  })

}(window.jQuery);

.form-group .boot-input {
  color: transparent;
}
.form-group .boot-input::-webkit-file-upload-button {
  visibility: hidden;
}
.form-group .boot-input::before {
  content: "\e204";
  font-family: 'Glyphicons Halflings';
  color: #444;
  display: inline-block;
  border: none;
  border-radius: 2px;
  margin: 0;
  padding: 0;
  outline: transparent;
  white-space: nowrap;
  -webkit-user-select: none;
  cursor: pointer;
  font-weight: 700;
  font-size: 10pt;
  float: right;
}
/*!
 * Jasny Bootstrap v3.1.3 (http://jasny.github.io/bootstrap)
 * Copyright 2012-2014 Arnold Daniels
 * Licensed under Apache-2.0 (https://github.com/jasny/bootstrap/blob/master/LICENSE)
 */

.container-smooth {
  max-width: 1170px;
}
@media (min-width: 1px) {
  .container-smooth {
    width: auto;
  }
}
.btn-labeled {
  padding-top: 0;
  padding-bottom: 0;
}
.btn-label {
  position: relative;
  left: -12px;
  display: inline-block;
  padding: 6px 12px;
  background: transparent;
  background: rgba(0, 0, 0, .15);
  border-radius: 3px 0 0 3px;
}
.btn-label.btn-label-right {
  right: -12px;
  left: auto;
  border-radius: 0 3px 3px 0;
}
.btn-lg .btn-label {
  left: -16px;
  padding: 10px 16px;
  border-radius: 5px 0 0 5px;
}
.btn-lg .btn-label.btn-label-right {
  right: -16px;
  left: auto;
  border-radius: 0 5px 5px 0;
}
.btn-sm .btn-label {
  left: -10px;
  padding: 5px 10px;
  border-radius: 2px 0 0 2px;
}
.btn-sm .btn-label.btn-label-right {
  right: -10px;
  left: auto;
  border-radius: 0 2px 2px 0;
}
.btn-xs .btn-label {
  left: -5px;
  padding: 1px 5px;
  border-radius: 2px 0 0 2px;
}
.btn-xs .btn-label.btn-label-right {
  right: -5px;
  left: auto;
  border-radius: 0 2px 2px 0;
}
.btn-file {
  position: relative;
  overflow: hidden;
  vertical-align: middle;
}
.btn-file > input {
  position: absolute;
  top: 0;
  right: 0;
  width: 100%;
  height: 100%;
  margin: 0;
  font-size: 23px;
  cursor: pointer;
  filter: alpha(opacity=0);
  opacity: 0;
  direction: ltr;
}
.fileinput {
  display: inline-block;
  margin-bottom: 9px;
}
.fileinput .form-control {
  display: inline-block;
  padding-top: 7px;
  padding-bottom: 5px;
  margin-bottom: 0;
  vertical-align: middle;
  cursor: text;
}
.fileinput .thumbnail {
  display: inline-block;
  margin-bottom: 5px;
  overflow: hidden;
  text-align: center;
  vertical-align: middle;
}
.fileinput .thumbnail > img {
  max-height: 100%;
}
.fileinput .btn {
  vertical-align: middle;
}
.fileinput-exists .fileinput-new,
.fileinput-new .fileinput-exists {
  display: none;
}
.fileinput-inline .fileinput-controls {
  display: inline;
}
.fileinput-filename {
  display: inline-block;
  overflow: hidden;
  vertical-align: middle;
}
.form-control .fileinput-filename {
  vertical-align: bottom;
}
.fileinput.input-group {
  display: table;
}
.fileinput.input-group > * {
  position: relative;
  z-index: 2;
}
.fileinput.input-group > .btn-file {
  z-index: 1;
}
.fileinput-new.input-group .btn-file,
.fileinput-new .input-group .btn-file {
  border-radius: 0 4px 4px 0;
}
.fileinput-new.input-group .btn-file.btn-xs,
.fileinput-new .input-group .btn-file.btn-xs,
.fileinput-new.input-group .btn-file.btn-sm,
.fileinput-new .input-group .btn-file.btn-sm {
  border-radius: 0 3px 3px 0;
}
.fileinput-new.input-group .btn-file.btn-lg,
.fileinput-new .input-group .btn-file.btn-lg {
  border-radius: 0 6px 6px 0;
}
.form-group.has-warning .fileinput .fileinput-preview {
  color: #8a6d3b;
}
.form-group.has-warning .fileinput .thumbnail {
  border-color: #faebcc;
}
.form-group.has-error .fileinput .fileinput-preview {
  color: #a94442;
}
.form-group.has-error .fileinput .thumbnail {
  border-color: #ebccd1;
}
.form-group.has-success .fileinput .fileinput-preview {
  color: #3c763d;
}
.form-group.has-success .fileinput .thumbnail {
  border-color: #d6e9c6;
}
.input-group-addon:not(:first-child) {
  border-left: 0;
}
/*# sourceMappingURL=jasny-bootstrap.css.map */

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css" rel="stylesheet" />
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"></script>
<div class="container">
  <h3>Jasny Plugin (Extracted)</h3>
  <div class="fileinput fileinput-new input-group" data-provides="fileinput">
    <div class="form-control" data-trigger="fileinput"><i class="glyphicon glyphicon-file fileinput-exists"></i>  <span class="fileinput-filename"></span>

    </div> <span class="input-group-addon btn btn-default btn-file"><span class="fileinput-new"><span class="glyphicon glyphicon-level-up"></span></span><span class="fileinput-exists">Change</span>

    <input type="file" name="...">
    </span> <a href="#" class="input-group-addon btn btn-default fileinput-exists" data-dismiss="fileinput">Remove</a>

  </div>

  <hr>
  <h3>Standalone CSS</h3>
  <div class="form-group">

    <input type="file" class="boot-input form-control" />

  </div>
</div>