Javascript：旋转木马活动点和左右按钮

Question

我是初级 javascript 开发人员。我决定使用纯 Javascript 来制作轮播。我成功地滑动了旋转木马。我决定制作活动点（也可点击），我希望在滑动发生和左右按钮时点背景颜色发生变化。我已经创建了点，但我不知道如何在我的滑动功能以及左右按钮中实现这些点。这是我的代码：

Also please explain me the logic. Thank you

const images = document.getElementById('imgs');
const allImages = document.querySelectorAll('#imgs img');
const leftBtn = document.getElementById('left');
const rightBtn = document.getElementById('right');
let index = 0;

function run() {
  const dot = [...document.getElementsByClassName('star')];
  index++;


  if (index > allImages.length - 1) {
    index = 0
    dot.forEach(i => i.classList.add('active'))
  }
  imgs.style.transform = `translateX(${-index * 500}px)`

}
const dot = allImages.forEach(i => {
  const elem = document.createElement('div');
  elem.classList.add('star');
  document.body.appendChild(elem)
})

let x = setInterval(run, 2000);

images.onmouseover = () => {
  clearInterval(x)
}
images.onmouseout = () => {
  x = setInterval(run, 2000);
}

*{
  box-sizing: border-box;
}

body {
  margin: 0;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
}

.carousel {
  overflow: hidden;
  width: 500px;
  height: 500px;
  box-shadow: 2px 2px 5px rgba(0, 0, 0, .3);
  border-radius: 5px;
}

.image-container {
  display: flex;
 transition: transform 300ms linear;
 transform: translateX(0);
}

img {
  width:500px;
  height: 500px;
  object-fit: cover;
}

.star{
  cursor: pointer;
  height: 15px;
  width: 15px;
  margin: 0 10px;
  border-radius: 50%;
  display: inline-block;
  transition: background-color 0.6s ease;
  background-color: #eeeeee;

}
.star.active{
  background-color: red;
}
button{
  cursor: pointer;
  position: relative;
  font-size: 18px;
  transition: 0.6s ease;
  user-select: none;
  height: 50px;
  width: 40px;
  display: flex;
  justify-content: center;
  align-items: center;
  align-content: center;
  top: calc(50% - 25px);
}
button:hover {
  background-color: rgba(0,0,0,0.8);
};

button.left {
  border-radius: 3px 0 0 3px;
  right: 0;
}
button.left {
  border-radius: 3px 0 0 3px;
  left: 0;
}

<button id="left">&#10094;</button>
  <button id="right">&#10095;</button>

  <div class="carousel">
    <div class="image-container" id="imgs" >
      <img src="https://images.unsplash.com/photo-1599736375341-51b0a848f3c7?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=800&q=60" alt="">
      <img src="https://images.unsplash.com/photo-1516026672322-bc52d61a55d5?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=800&q=60" alt="">
      <img src="https://images.unsplash.com/photo-1573081586928-127ecc7948b0?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=800&q=60" alt="">
      <img src="https://images.unsplash.com/flagged/photo-1572850005109-f4ac7529bf9f?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=800&q=60" alt="">
    </div>
  </div>

Answer 1

你离结果很近了。在您的 run 函数中，您只需更改当前活动 dot 的 class 并将新的设置为活动。为了便于理解，我将您的 dot 变量重命名为 dots。

function run() {
  const dots = [...document.getElementsByClassName('star')];
  index++;


  if (index > allImages.length - 1) {
    index = 0
  }
  
  dots.forEach((dot, i) => {
    if (dot.classList.contains('active')) dot.classList.remove('active');
    if (i === index) dot.classList.add('active'));
  }
  imgs.style.transform = `translateX(${-index * 500}px)`

}

Javascript：旋转木马活动点和左右按钮

Javascript: Carousel active dots and left-right buttons

html

javascript

css

carousel