简单的轮播prev / next jQuery函数-prev函数不起作用

编程问答 2022-06-08

问题描述

以下轮播中的“ PREV” jquery函数有问题，请帮忙。

<div id="carousel">
    <div id="product-detail-image-wrapper">
        <div id="product-detail-image-inner-wrapper">
            <img class="product-detail-image" src="images/01.jpg" />
            <img class="product-detail-image" src="images/02.jpg" />
            <img class="product-detail-image" src="images/03.jpg" />
            <img class="product-detail-image" src="images/04.jpg" />
            <img class="product-detail-image" src="images/05.jpg" />
        </div>
        <img id="image-control-left" src="images/left-arrow.png" onclick="showPrev();" />
        <img id="image-control-right" src="images/right-arrow.png" onclick="showNext();" />                         
    </div>
</div>

showNext（）函数运行完美。但是showPrev（）无法正常工作。

在开始时，只会显示第一张图像，而不会显示其他图像。

$(document).ready(function(){
    //hide all the images except the first one...
    $('#product-detail-image-inner-wrapper img:gt(0)').hide();
});

function showNext() {
    $('#product-detail-image-inner-wrapper :first-child').fadeOut()
        .next('img').fadeIn()
        .end().appendTo('#product-detail-image-inner-wrapper');                     
    
}

function showPrev() {
    $('#product-detail-image-inner-wrapper :first-child').fadeOut()
         .last('img').fadeIn()
         .end().prependTo('#product-detail-image-inner-wrapper');                       
}

谁能告诉我showPrev（）函数中的错误是什么？我尝试了很多次，但是没有用。非常感谢。

在showNext（）函数中，单击“下一个”按钮时，图像“ 01”将淡出，图像“ 02”将淡入，然后图像“ 01”将如下所示转到列表的末尾： / p> 

<div id="product-detail-image-inner-wrapper">
    <img class="product-detail-image" src="images/02.jpg" />
    <img class="product-detail-image" src="images/03.jpg" />
    <img class="product-detail-image" src="images/04.jpg" />
    <img class="product-detail-image" src="images/05.jpg" />
    <img class="product-detail-image" src="images/01.jpg" />
</div>

上面的最后4行将设置为“ display：none;”。 我期望在showPrev（）函数的反向模式中具有相同的行为。

解决方法

如果打开DevTols，您会看到未选择正确的图像，也未正确移动到第一位。

向后移动时，您需要：淡出第一张图像，找到最后一张，将其淡入并移动到第一位置。

function showPrev() {
  $('#product-detail-image-inner-wrapper :first-child').fadeOut()
    .nextAll('img:last-of-type').fadeIn().end();
  $("#product-detail-image-inner-wrapper :last-child").prependTo('#product-detail-image-inner-wrapper');
}

工作示例： 

$(document).ready(function() {
  //hide all the images except the first one...
  $('#product-detail-image-inner-wrapper img:gt(0)').hide();
});

function showNext() {
  $('#product-detail-image-inner-wrapper :first-child').fadeOut()
    .next('img').fadeIn()
    .end().appendTo('#product-detail-image-inner-wrapper');

}

function showPrev() {
  $('#product-detail-image-inner-wrapper :first-child').fadeOut()
    .nextAll('img:last-of-type').fadeIn().end();
  $("#product-detail-image-inner-wrapper :last-child").prependTo('#product-detail-image-inner-wrapper');
}
img {
  max-width: 200px;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div id="carousel">
  <div id="product-detail-image-wrapper">
    <div id="product-detail-image-inner-wrapper">
      <img class="product-detail-image" src="https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Ftse1.mm.bing.net%2Fth%3Fid%3DOIP.dAEeeFKKWyKvfi09BT_b7QHaFj%26pid%3DApi&f=1" title="1" />
      <img class="product-detail-image" src="https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Ftse1.mm.bing.net%2Fth%3Fid%3DOIP.hUrigs4oGP1BPza_niQmnQHaFh%26pid%3DApi&f=1" title="2" />
      <img class="product-detail-image" src="https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Ftse1.mm.bing.net%2Fth%3Fid%3DOIP.w4J0Joa9SQJjntfW3Bl2kgHaD5%26pid%3DApi&f=1" title="3" />
      <img class="product-detail-image" src="https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Ftse1.mm.bing.net%2Fth%3Fid%3DOIP.QEM5dAvEzjYwaND5AmgsQgHaEM%26pid%3DApi&f=1" title="4" />
      <img class="product-detail-image" src="https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Ftse1.mm.bing.net%2Fth%3Fid%3DOIP.loIp0wgsX2e_eppiqs-pvgHaHa%26pid%3DApi&f=1" title="5" />
    </div>
    <button id="image-control-left" onclick="showPrev();">-</button>
    <button id="image-control-right" onclick="showNext();">+</button>
  </div>
</div>

,

这是与图像搭配的烤面包机的标准代码。

  <html>
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
    <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js" integrity="sha384-JZR6Spejh4U02d8jOt6vLEHfe/JQGiRRSQQxSfFWpi1MquVdAyjUar5+76PVCmYl" crossorigin="anonymous"></script>
    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">
    <div id="carouselExampleIndicators" class="carousel slide" data-ride="carousel">
        <ol class="carousel-indicators">
          <li data-target="#carouselExampleIndicators" data-slide-to="0" class="active"></li>
          <li data-target="#carouselExampleIndicators" data-slide-to="1"></li>
          <li data-target="#carouselExampleIndicators" data-slide-to="2"></li>
          <li data-target="#carouselExampleIndicators" data-slide-to="3"></li>
          <li data-target="#carouselExampleIndicators" data-slide-to="4"></li>
        </ol>
        <div class="carousel-inner">
          <div class="carousel-item active">
            <img class="d-block w-100" src="images/01.jpg" alt="slide 1">
          </div>
          <div class="carousel-item">
            <img class="d-block w-100" src="images/02.jpg" alt="slide 2">
          </div>
          <div class="carousel-item">
            <img class="d-block w-100" src="images/03.jpg" alt="slide 3">
          </div>
          <div class="carousel-item">
            <img class="d-block w-100" src="images/04.jpg" alt="slide 4">
          </div>
          <div class="carousel-item">
            <img class="d-block w-100" src="images/05.jpg" alt="slide 5">
          </div>
        </div>
        <a class="carousel-control-prev" href="#carouselExampleIndicators" role="button" data-slide="prev">
          <span class="carousel-control-prev-icon" aria-hidden="true"></span>
          <span class="sr-only">Previous</span>
        </a>
        <a class="carousel-control-next" href="#carouselExampleIndicators" role="button" data-slide="next">
          <span class="carousel-control-next-icon" aria-hidden="true"></span>
          <span class="sr-only">Next</span>
        </a>
      </div>
      </html>

carouseljquery