javascript – Materialise css选择不使用JS错误

<div class="input-field col s12">
    <select multiple>
        <option value="" disabled selected>Choose your option</option>
        <option value="1">Option 1</option>
        <option value="2">Option 2</option>
        <option value="3">Option 3</option>
    </select>
    <label>Materialize Multiple Select</label>
</div>

<script src="//code.jquery.com/jquery-2.1.2.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/materialize/0.97.5/js/materialize.min.js"></script>

<script>
    $('select').material_select();
</script>

这是我的苗条布局：

doctype html
html
  head
    Meta content=("text/html; charset=UTF-8") http-equiv="Content-Type" /
    title Budeprace
    = stylesheet_link_tag    'https://cdnjs.cloudflare.com/ajax/libs/materialize/0.97.5/css/materialize.min.css',media: 'screen,projection'
    = stylesheet_link_tag    'http://fonts.googleapis.com/icon?family=Material+Icons'
    = stylesheet_link_tag    'application',media: 'all','data-turbolinks-track' => true
    = javascript_include_tag 'application','data-turbolinks-track' => true
    = csrf_Meta_tags
    Meta content="width=device-width,initial-scale=1.0" name="viewport"

  body
    .container
      - flash.each do |key,value|
        div class=("text-center #{flash_class(key)}") 
          = value

      = yield

      = javascript_include_tag 'http://cdnjs.cloudflare.com/ajax/libs/materialize/0.97.5/js/materialize.min.js'
      = javascript_include_tag 'http://code.jquery.com/jquery-2.1.2.min.js'

如果我从布局中删除两个.js脚本,SELECT工作.如果我将从表单中删除这两个脚本并将它们保留在布局中,则SELECT将不再适用于浏览器中的以下错误：

"job:65 Uncaught TypeError: $(...).material_select is not a function"

即使我将以这种方式将它放到application.js,错误仍然存​​在：

$(document).ready(function() {
    $('select').material_select();
  });

知道什么是错的吗？我在实现中遇到了很多选择和下拉问题,但无法弄明白.

谢谢.