javascript - 为旋转木马创建循环的问题 - 回到第一个元素

Question

我在轮播内创建循环时遇到问题，因此它会在点击事件 - rightButton 到达最后一张卡片后返回第一张卡片。到目前为止，轮播在到达最后一张卡片时停止。

const carousel = document.querySelector("[data-target='carousel']");
const card = carousel.querySelector("[data-target='card']");
const leftButton = document.querySelector("[data-action='slideLeft']");
const rightButton = document.querySelector("[data-action='slideRight']");

const carouselWidth = carousel.offsetWidth;
const cardStyle = card.currentStyle || window.getComputedStyle(card)
const cardMarginRight = Number(cardStyle.marginRight.match(/\d+/g)[0]);

const cardCount = carousel.querySelectorAll("[data-target='card']").length;

let offset = 0;
const maxX = -((cardCount / 3) * carouselWidth + 
               (cardMarginRight * (cardCount / 3)) - 
               carouselWidth - cardMarginRight);


leftButton.addEventListener("click", function() {
  if (offset !== 0) {
    offset += carouselWidth + cardMarginRight;
    carousel.style.transform = `translateX(${offset}px)`;
    }
})
  
rightButton.addEventListener("click", function() {
  if (offset !== maxX) {
    offset -= carouselWidth + cardMarginRight;
    carousel.style.transform = `translateX(${offset}px)`;
  }
})

.wrapper {
  height: 100px;
  width: 432px;
  position: relative;
  overflow: hidden;
  margin: 0 auto;
}

.button-wrapper {
  width: 100%;
  height: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: absolute;
}

.carousel {
  margin: 0;
  padding: 0;
  list-style: none;
  width: 100%;
  display: flex;
  position: absolute;
  left: 0;
  transition: all 1s ease;
}

.card {
  background: black;
  min-width: 100px;
  height: 100px;
  margin-right: 1rem;
  display: inline-block;
}

span {
  color:#ffffff;
}

<div class="wrapper">
  <ul class="carousel" data-target="carousel">
    <li class="card" data-target="card"><span>1</span></li>
    <li class="card" data-target="card"><span>2</span></li>
    <li class="card" data-target="card"><span>3</span></li>
    <li class="card" data-target="card"><span>4</span></li>
    <li class="card" data-target="card"><span>5</span></li>
    <li class="card" data-target="card"><span>6</span></li>
    <li class="card" data-target="card"><span>7</span></li>
    <li class="card" data-target="card"><span>8</span></li>
    <li class="card" data-target="card"><span>9</span></li>
  </ul>
  <div class="button-wrapper">
    <button data-action="slideLeft">L</button>
    <button data-action="slideRight">R</button>
  </div>
</div>

jsfiddle 上可用的代码: https://jsfiddle.net/2qv6mpb1/

是否有人可以为我指明正确的方向以实现这一目标？我

Answer 1

您需要处理当您的偏移量等于 maxX 时，并将偏移量重置为零。

rightButton.addEventListener("click", function() {
  if (offset !== maxX) {
    offset -= carouselWidth + cardMarginRight;
    carousel.style.transform = `translateX(${offset}px)`;
  } else {
    offset = 0;
    carousel.style.transform = `translateX(${offset}px)`;
  }
})