Question

所以我在桌子末尾添加了一个下拉按钮，出于某种原因，当我点击它时，没有任何东西掉下来。我看到我的控制台上也没有错误。我的CSS中有什么东西可以阻止它工作吗？

HTML代码：

<!DOCTYPE html>
<html lang="en">
<head>
  <link rel="stylesheet" type="text/css" href="http://netdna.bootstrapcdn.com/bootstrap/3.0.0/css/bootstrap.min.css">
  <link rel="stylesheet" type="text/css" href="http://netdna.bootstrapcdn.com/font-awesome/3.2.1/css/font-awesome.min.css">
  <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js" type="text/javascript"></script>
  <link rel="stylesheet" type="text/css" href="public/stylesheets/grayscale.css">
  <title>tech</title>
</head>

<body>
<div id="Tech" class="header">
  <center><img src="public/images/test.png" id='Logo' alt="Logo">
  </center>
</div>

<form id="upload" action="index.html" method="POST" enctype="multipart/form-data">
<fieldset>
<input type="hidden" id="MAX_FILE_SIZE" name="MAX_FILE_SIZE" value="300000" />
<div>
    <div id="filedrag"> 
        <img src="public/images/upload3.png" alt="draganddrop"> 
    </div>
    <input type="file" id="fileselect" name="fileselect[]" multiple="multiple"/>
</div>
</fieldset>
</form>

<div id="messages">
</div>

<table id="data-table" class="container">
  <thead>
    <tr>
      <th>
        <h3>Video</h3>
      </th>
      <th>
        <h3>Original Size</h3>
      </th>
      <th>
        <h3>Compressed Size</h3>
      </th>
      <th>
        <h3>Compressed rate</h3>
      </th>
      <th>
        <h3>Savings</h3>
      </th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>Video1 File Name</td>
      <td>Original File Size</td>
      <td>6369</td>
      <td>01:32:50</td>
      <td>450</td>      
      <td>
        <div class="container">
          <div class="dropdown">
            <button class="btn btn-success dropdown-toggle" type="button" data-toggle="dropdown">Compress
            <span class="caret"></span></button>
            <ul class="dropdown-menu">
              <li><a href="#">Compress</a></li>
              <li class="disabled"><a href="#">Download</a></li>
              <li class="active"><a href="#">Delete</a></li>
            </ul>
          </div>
        </div>        
      </td>
    </tr>
    <tr>
      <td>Video 2 File Name</td>
      <td>Original File Size</td>
      <td>10437</td>
      <td>00:51:22</td>
      <td>450</td>
      <td>
        <div class="container">
          <div class="dropdown">
            <button class="btn btn-success dropdown-toggle" type="button" data-toggle="dropdown">Compress
            <span class="caret"></span></button>
            <ul class="dropdown-menu">
              <li><a href="#">Compress</a></li>
              <li class="disabled"><a href="#">Download</a></li>
              <li class="active"><a href="#">Delete</a></li>
            </ul>
          </div>
        </div>               
      </td>
    </tr>
    <tr>
      <td>Video 3 File Name</td>
      <td>Original File Size</td>
      <td>5327</td>
      <td>00:24:34</td>
      <td>450</td>
      <td>
        <div class="container">
          <div class="dropdown">
            <button class="btn btn-success dropdown-toggle" type="button" data-toggle="dropdown">Compress
            <span class="caret"></span></button>
            <ul class="dropdown-menu">
              <li><a href="#">Compress</a></li>
              <li class="disabled"><a href="#">Download</a></li>
              <li class="active"><a href="#">Delete</a></li>
            </ul>
          </div>
        </div>        
      </td>
    </tr>
  </tbody>
</table>

</body>
<script src="public/js/filedrag.js"></script>
</html>

CSS代码：

@charset "UTF-8";
@import url(http://fonts.googleapis.com/css?family=Open+Sans:300,400,700);

body {
  font-family: 'Open Sans', sans-serif;
  font-weight: 300;
  line-height: 1.42em;
  color:#A7A1AE;
  background-color:#1F2739;
}

.data-table{
    margin-top: 250px;
}

#filedrag{
    text-align: center;
    border-radius: 7px;
    cursor: default;
}

#filedrag.hover{
    color: #f00;
    border-color: #f00;
    border-style: solid;
    box-shadow: inset 0 3px 4px #888;
}

#title{
    text-align: center;
}

#logo{
    float: right;
}

.header img {
    float:left;
    border: 5px;
    padding:5px;
    width: 4em;
    height: 4em;
    border-radius: 10px;
}

.header h1 {
  position:relative;
  font-size:3em; 
  font-weight: 300;
  line-height:1em;
  text-align: left;
  color: #FFFFFF;
}

h1 {
  font-size:3em; 
  font-weight: 300;
  line-height:1em;
  text-align: center;
  color: #FFFFFF;
}

h2 {
  font-size:1em; 
  font-weight: 300;
  text-align: center;
  display: block;
  line-height:1em;
  padding-bottom: 2em;
  color: #FB667A;
}

h2 a {
  font-weight: 700;
  text-transform: uppercase;
  color: #FB667A;
  text-decoration: none;
}

h3{
    color: white;
}

h4{
    text-align: center;
    font-size: 2em;
}

#Register
{
    margin-left: 750px;
    margin-top: 27px;
}
.btn-update{
    position: absolute;
    bottom: 0;
    margin-bottom: 300px;
    margin-left: -65px;
}

.hideshow{
    position: absolute;
    bottom: 0;
    margin-bottom: 300px;
    margin-left: -65px;
}

.blue { color: #185875; }
.yellow { color: #FFF842; }

.container th h1 {
      font-weight: bold;
      font-size: 1em;
  text-align: left;
  color: #185875;
}

.container td {
      font-weight: normal;
      font-size: 1em;
  -webkit-box-shadow: 0 2px 2px -2px #0E1119;
       -moz-box-shadow: 0 2px 2px -2px #0E1119;
            box-shadow: 0 2px 2px -2px #0E1119;
}

.container {
      text-align: left;
      overflow: hidden;
      width: 80%;
      margin: 0 auto;
  display: table;
  padding: 0 0 8em 0;
}

.container td, .container th {
    padding-bottom: 2%;
    padding-top: 2%;
    padding-left:2%;  
}

/* Background-color of the odd rows */
.container tr:nth-child(odd) {
      background-color: #323C50;
}

/* Background-color of the even rows */
.container tr:nth-child(even) {
      background-color: #2C3446;
}

.container th {
      background-color: #1F2739;
}

.container_graph {
  width: 80%;
  margin: 15px auto;
  margin-top: 175px;
}

.container td:first-child { color: #FB667A; }

.container tr:hover {
   background-color: #464A52;
-webkit-box-shadow: 0 6px 6px -6px #0E1119;
       -moz-box-shadow: 0 6px 6px -6px #0E1119;
            box-shadow: 0 6px 6px -6px #0E1119;
}

.container td:hover {
  /*background-color: #FFF842;*/
  /*color: #403E10;*/


  transition-delay: 0s;
      transition-duration: 0.4s;
      transition-property: all;
  transition-timing-function: line;
}

@media (max-width: 800px) {
.container td:nth-child(4),
.container th:nth-child(4) { display: none; }
}

Answer 1

确保加载bootstrap.js，因为下拉列表需要bootstrap.js才能运行。

css文件主要用于设置控件样式，但真正的交互由JavaScript文件处理。

Answer 2

看下面的代码片段它运行正常。按下面提到的顺序添加cdn。

<link rel="stylesheet"   
href="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css">
      <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>
      <script src="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js"></script>

<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1">
 <link rel="stylesheet" href="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css">
          <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>
          <script src="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js"></script>
           <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css">
           <style type="text/css">
             

           </style>
           </head>
           <body>
           <div id="Tech" class="header">
  <center><img src="public/images/test.png" id='Logo' alt="Logo">
  </center>
</div>

<form id="upload" action="index.html" method="POST" enctype="multipart/form-data">
<fieldset>
<input type="hidden" id="MAX_FILE_SIZE" name="MAX_FILE_SIZE" value="300000" />
<div>
    <div id="filedrag"> 
        <img src="public/images/upload3.png" alt="draganddrop"> 
    </div>
    <input type="file" id="fileselect" name="fileselect[]" multiple="multiple"/>
</div>
</fieldset>
</form>

<div id="messages">
</div>

<table id="data-table" class="container">
  <thead>
    <tr>
      <th>
        <h3>Video</h3>
      </th>
      <th>
        <h3>Original Size</h3>
      </th>
      <th>
        <h3>Compressed Size</h3>
      </th>
      <th>
        <h3>Compressed rate</h3>
      </th>
      <th>
        <h3>Savings</h3>
      </th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>Video1 File Name</td>
      <td>Original File Size</td>
      <td>6369</td>
      <td>01:32:50</td>
      <td>450</td>      
      <td>
        <div class="container">
          <div class="dropdown">
            <button class="btn btn-success dropdown-toggle" type="button" data-toggle="dropdown">Compress
            <span class="caret"></span></button>
            <ul class="dropdown-menu">
              <li><a href="#">Compress</a></li>
              <li class="disabled"><a href="#">Download</a></li>
              <li class="active"><a href="#">Delete</a></li>
            </ul>
          </div>
        </div>        
      </td>
    </tr>
    <tr>
      <td>Video 2 File Name</td>
      <td>Original File Size</td>
      <td>10437</td>
      <td>00:51:22</td>
      <td>450</td>
      <td>
        <div class="container">
          <div class="dropdown">
            <button class="btn btn-success dropdown-toggle" type="button" data-toggle="dropdown">Compress
            <span class="caret"></span></button>
            <ul class="dropdown-menu">
              <li><a href="#">Compress</a></li>
              <li class="disabled"><a href="#">Download</a></li>
              <li class="active"><a href="#">Delete</a></li>
            </ul>
          </div>
        </div>               
      </td>
    </tr>
    <tr>
      <td>Video 3 File Name</td>
      <td>Original File Size</td>
      <td>5327</td>
      <td>00:24:34</td>
      <td>450</td>
      <td>
        <div class="container">
          <div class="dropdown">
            <button class="btn btn-success dropdown-toggle" type="button" data-toggle="dropdown">Compress
            <span class="caret"></span></button>
            <ul class="dropdown-menu">
              <li><a href="#">Compress</a></li>
              <li class="disabled"><a href="#">Download</a></li>
              <li class="active"><a href="#">Delete</a></li>
            </ul>
          </div>
        </div>        
      </td>
    </tr>
  </tbody>
</table>
  </body>
  </html>

Bootstrap下拉按钮不下降

2 个答案: