自定义slick.js时第一张幻灯片中的问题

Question

我将在slick.js的帮助下制作一个滑块。我还在此项目中使用Bootstrap和jQuery。

此滑块显示完整的两张幻灯片，显示一半的一半。所选的每个幻灯片都具有active类，并保持该类，直到它脱离两个完整的幻灯片模式。我没有实现此滑块的问题，除第一张幻灯片外，所有幻灯片都可以正常工作。问题在于，当第一张幻灯片在全模式之间切换时，它会丢失其active类并重新获得它。

代码插入此处：

//slick slider initial
$('.slider').slick({
  infinite: true,
  slidesToShow: 2,
  slidesToScroll: 1,
});

// slick "beforeChange" event
$('.slider').on('beforeChange', function(event, slick, currentSlide, nextSlide) {
  let activeIndex = $(this).find('.active').attr('data-index');
  let zoneIndexes = (nextSlide >= slick.slideCount - 1) ? [nextSlide, 0] : [nextSlide, nextSlide + 1];

  console.log('active index: ' + activeIndex + ' , zone indexes: ' + zoneIndexes)

  if (typeof activeIndex !== "undefined" && !(activeIndex == zoneIndexes[0] || activeIndex == zoneIndexes[1])) {
    $('.slide').removeClass('active');
  }
});


$('.selector').on('click', function() {
  $('.slide').removeClass('active');
  $(this).parent().addClass('active');
});

.slide {
  height: 400px;
  text-align: center;
  line-height: 200px;
  font-weight: bold;
  font-size: 25px;
  color: white;
  border: 4px solid transparent;
  display: flex;
  flex-direction: column;
}

.blue {
  background-color: blue;
}

.red {
  background-color: red;
}

.green {
  background-color: green;
}

.cyan {
  background-color: cyan;
}

.slick-list {
  padding-right: 20%!important;
}

.slide.active {
  color: gold;
  font-size: 35px;
  border: 4px solid gold;
}

.selector {
  padding: 10px 20px;
  background-color: black;
  color: white;
  cursor: pointer;
}

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/slick-carousel/1.9.0/slick.min.css">

<div class="container">
  <div class="row">
    <div class="col-12 slider">
      <div class="slide red" data-index="0">SLIDE 0<span class="selector">select me</span></div>
      <div class="slide blue" data-index="1">SLIDE 1<span class="selector">select me</span></div>
      <div class="slide green" data-index="2">SLIDE 2<span class="selector">select me</span></div>
      <div class="slide cyan" data-index="3">SLIDE 3<span class="selector">select me</span></div>
    </div>
  </div>
</div>




<script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js" integrity="sha384-ApNbgh9B+Y1QKtv3Rn7W3mgPxhU9K/ScQsAP7hUibX39j7fakFPskvXusvfa0b4Q" crossorigin="anonymous"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js" integrity="sha384-JZR6Spejh4U02d8jOt6vLEHfe/JQGiRRSQQxSfFWpi1MquVdAyjUar5+76PVCmYl" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/slick-carousel/1.9.0/slick.min.js"></script>

感谢您的帮助。

Answer 1

我不知道为什么滑片会这样对待第一张幻灯片，但是我找到了这个问题的简短答案：

//slick slider initial
$('.slider').slick({
  infinite: true,
  slidesToShow: 2,
  slidesToScroll: 1,
});

// slick "beforeChange" event
$('.slider').on('beforeChange', function(event, slick, currentSlide, nextSlide) {
  let activeIndex = $(this).find('.active').attr('data-index');
  let zoneIndexes = (nextSlide >= slick.slideCount - 1) ? [nextSlide, 0] : [nextSlide, nextSlide + 1];

  if (activeIndex == 0) {
    $(this).find('.slide[data-index=0]').addClass('active')
  }

  console.log('active index: ' + activeIndex + ' , zone indexes: ' + zoneIndexes)

  if (typeof activeIndex !== "undefined" && !(activeIndex == zoneIndexes[0] || activeIndex == zoneIndexes[1])) {
    $('.slide').removeClass('active');
  }
});


$('.selector').on('click', function() {
  $('.slide').removeClass('active');
  $(this).parent().addClass('active');
});

.slide {
  height: 400px;
  text-align: center;
  line-height: 200px;
  font-weight: bold;
  font-size: 25px;
  color: white;
  border: 4px solid transparent;
  display: flex;
  flex-direction: column;
}

.blue {
  background-color: blue;
}

.red {
  background-color: red;
}

.green {
  background-color: green;
}

.cyan {
  background-color: cyan;
}

.slick-list {
  padding-right: 20%!important;
}

.slide.active {
  color: gold;
  font-size: 35px;
  border: 4px solid gold;
}

.selector {
  padding: 10px 20px;
  background-color: black;
  color: white;
  cursor: pointer;
}

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/slick-carousel/1.9.0/slick.min.css">

<div class="container">
  <div class="row">
    <div class="col-12 slider">
      <div class="slide red" data-index="0">SLIDE 0<span class="selector">select me</span></div>
      <div class="slide blue" data-index="1">SLIDE 1<span class="selector">select me</span></div>
      <div class="slide green" data-index="2">SLIDE 2<span class="selector">select me</span></div>
      <div class="slide cyan" data-index="3">SLIDE 3<span class="selector">select me</span></div>
    </div>
  </div>
</div>


<script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js" integrity="sha384-ApNbgh9B+Y1QKtv3Rn7W3mgPxhU9K/ScQsAP7hUibX39j7fakFPskvXusvfa0b4Q" crossorigin="anonymous"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js" integrity="sha384-JZR6Spejh4U02d8jOt6vLEHfe/JQGiRRSQQxSfFWpi1MquVdAyjUar5+76PVCmYl" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/slick-carousel/1.9.0/slick.min.js"></script>