用jQuery动画图像更改

Question

我试图从div中为img更改添加动画，并且尝试使用jquery这样做，因为这似乎是最干净的方法。 我尝试使用此答案，但没有成功。 我的方法哪里出错了？

HTML：

 <div class="jumbotron text-center" id="main-jum">
    <img id="jum-img" src = "https://im.whatshot.in/img/2017/Oct/churrosweb-1509092812.jpg">
 </div>


  <div class="container-fluid text-center d-none d-md-block" id="jum-btns">
     <div id="jum-btn" class="btn-group " role="group" aria-label="Basic example">
      <button type="button" id="btn-left" class="btn btn-secondary jum-btn" onclick="changeColor();">Left</button>
      <button type="button" id="btn-middle" class="btn btn-secondary jum-btn" onclick="changeColor();">Middle</button>
      <button type="button" id="btn-right" class="btn btn-secondary jum-btn" onclick="changeColor();">Right</button>
    </div>
  </div>

<script type="text/javascript">
$(document).ready(function(){
  $('#btn-left').click(function() {
   $('#jum-img').fadeOut(500, function() {
       $('#jum-img').attr("src","https://truffle-assets.imgix.net/pxqrocxwsjcc_5pcvIMJdpmi8COGYQ0kua6_churros-with-dulce-de-leche_landscapeThumbnail_en-US.jpeg");
       $('#jum-img').fadeIn(500);
     });
  });
});
</script>

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>

Codepen

Answer 1

您正在调用“＃jum-Img”，但您的ID实际上是“＃jum-img”，将I更改为小写字母后，您的代码就可以工作了。

Answer 2

很简单。 只需将所有js和脚本放在HTML代码之前。

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
<script>
$(document).ready(function(){
  $('#btn-left').click(function() {
   $('#jum-img').fadeOut(500, function() {
       $('#jum-img').attr("src","https://truffle-assets.imgix.net/pxqrocxwsjcc_5pcvIMJdpmi8COGYQ0kua6_churros-with-dulce-de-leche_landscapeThumbnail_en-US.jpeg");
       $('#jum-img').fadeIn(500);
     });
  });
});
</script>

<div class="jumbotron text-center" id="main-jum">
    <img id="jum-img" src = "https://im.whatshot.in/img/2017/Oct/churrosweb-1509092812.jpg">
 </div>
  <div class="container-fluid text-center d-none d-md-block" id="jum-btns">
     <div id="jum-btn" class="btn-group " role="group" aria-label="Basic example">
      <button type="button" id="btn-left" class="btn btn-secondary jum-btn" onclick="changeColor();">Left</button>
      <button type="button" id="btn-middle" class="btn btn-secondary jum-btn" onclick="changeColor();">Middle</button>
      <button type="button" id="btn-right" class="btn btn-secondary jum-btn" onclick="changeColor();">Right</button>
    </div>
  </div>