JavaScript slider 无法正常工作

Question

我正在尝试制作一个 slider ，但我遇到了一个问题:slideWidth 变量(即幻灯片的宽度)总是相同的，所以当它到达第二个时slide 不想再往前走，和之前的 slide 一样，因为固定的变量值，它会滑到空白处。 + 它不想动画。如何解决这个问题？

请查看代码:

// Slider
const slider_wrapp = document.querySelector('.tract-slider');
const slider = document.querySelector('.tract-slider-wrapp');
var slide = document.getElementsByClassName('tract-slide');

const leftBtn = document.querySelector('.slide-left');
const rightBtn = document.querySelector('.slide-right');

let swWidth = slider_wrapp.clientWidth;
let sliderWidth = swWidth * slide.length;
let slideWidth = swWidth;

slider.style.width = sliderWidth + "px";

for (var i = 0; i < slide.length; i++) {
  slide.item(i).style.width = " " + swWidth + "px";
}

function moveRight() {
  slider.style.transform = "translateX(" + (-slideWidth) + "px)";
}

function moveLeft() {
  slider.style.transform = "translateX(" + (slideWidth) + "px)";
}

rightBtn.addEventListener("click", function() {
  moveRight()
});

leftBtn.addEventListener("click", function() {
  moveLeft();
});

.tract-slider {
  width: 100%;
  height: 75vh;
  position: relative;
  overflow: hidden;
}

.tract-slider-wrapp {
  height: 100%;
  position: relative;
  -webkit-transition: translate 350ms cubic-bezier(.08, .13, 0, .81);
  -o-transition: translate 350ms cubic-bezier(.08, .13, 0, .81);
  transition: translate 350ms cubic-bezier(.08, .13, 0, .81);
}

.tract-slide {
  height: 100%;
  float: left;
  position: relative;
  display: block;
  background-position: center;
  -webkit-background-size: cover;
  background-size: cover;
}

.tract-slide:nth-child(1) {
  background-image: url("https://static.pexels.com/photos/126282/pexels-photo-126282.jpeg");
}

.tract-slide:nth-child(2) {
  background-image: url("https://static.pexels.com/photos/29017/pexels-photo-29017.jpg");
}

.tract-slide:nth-child(3) {
  background-image: url("https://static.pexels.com/photos/70760/dandelion-dandelion-seeds-taraxacum-fluffy-70760.jpeg");
}

.tract-slider-control {
  position: absolute;
  left: 0;
  bottom: 0;
  background: #ffffff;
  padding: 1em;
}

.tract-slider-btn {
  display: inline-block;
  cursor: pointer;
  margin-left: 1em;
}

.tract-slider-btn:nth-child(1) {
  margin-left: 0;
}

<div class="tract-slider">
  <div class="tract-slider-wrapp">
    <div class="tract-slide"></div>
    <div class="tract-slide"></div>
    <div class="tract-slide"></div>
  </div>
  <div class="tract-slider-control">
    <div class="tract-slider-btn slide-left">Prev</div>
    <div class="tract-slider-btn slide-right">Next</div>
  </div>
</div>

P.S. If you know the solution please write it in JavaScript not JQuery

Answer 1

您的问题是您错过了计算 slideWrapper 的 translateX 位置:(slideWidth var)

要修复它，您必须检查并分配一个新的计算值，而不是始终将其设置为 slider 宽度。

请注意，我在 moveRight() 和 moveLeft() 中都添加了计算

请参阅下面的工作片段:(仅使用 js)

// Slider
const slider_wrapp = document.querySelector('.tract-slider');
const slider = document.querySelector('.tract-slider-wrapp');
var slide = document.getElementsByClassName('tract-slide');

const leftBtn = document.querySelector('.slide-left');
const rightBtn = document.querySelector('.slide-right');

let swWidth = slider_wrapp.clientWidth;
let sliderWidth = swWidth * slide.length;
let slideWidth = 0;

slider.style.width = sliderWidth + "px";

for (var i = 0; i < slide.length; i++) {
  slide.item(i).style.width = " " + swWidth + "px";
}

function moveRight() {
  slideWidth === sliderWidth - swWidth ? slideWidth = 0 : slideWidth += swWidth;
  slider.style.transform = "translateX(" + (-slideWidth) + "px)";
}

function moveLeft() {  
  slideWidth === 0 ? slideWidth = sliderWidth-swWidth :  slideWidth -= swWidth;
  slider.style.transform = "translateX(" + (-slideWidth) + "px)";
}

rightBtn.addEventListener("click", function() {
  moveRight()
});

leftBtn.addEventListener("click", function() {
  moveLeft();
});

.tract-slider {
  width: 100%;
  height: 75vh;
  position: relative;
  overflow: hidden;
}

.tract-slider-wrapp {
  height: 100%;
  position: relative;
  -webkit-transition: all 350ms cubic-bezier(.08, .13, 0, .81);
  -o-transition: all 350ms cubic-bezier(.08, .13, 0, .81);
  transition: all 350ms cubic-bezier(.08, .13, 0, .81);
}

.tract-slide {
  height: 100%;
  float: left;
  position: relative;
  display: block;
  background-position: center;
  -webkit-background-size: cover;
  background-size: cover;
}

.tract-slide:nth-child(1) {
  background-image: url("https://static.pexels.com/photos/126282/pexels-photo-126282.jpeg");
}

.tract-slide:nth-child(2) {
  background-image: url("https://static.pexels.com/photos/29017/pexels-photo-29017.jpg");
}

.tract-slide:nth-child(3) {
  background-image: url("https://static.pexels.com/photos/70760/dandelion-dandelion-seeds-taraxacum-fluffy-70760.jpeg");
}

.tract-slider-control {
  position: absolute;
  left: 0;
  bottom: 0;
  background: #ffffff;
  padding: 1em;
}

.tract-slider-btn {
  display: inline-block;
  cursor: pointer;
  margin-left: 1em;
}

.tract-slider-btn:nth-child(1) {
  margin-left: 0;
}

<div class="tract-slider">
  <div class="tract-slider-wrapp">
    <div class="tract-slide"></div>
    <div class="tract-slide"></div>
    <div class="tract-slide"></div>
  </div>
  <div class="tract-slider-control">
    <div class="tract-slider-btn slide-left">Prev</div>
    <div class="tract-slider-btn slide-right">Next</div>
  </div>
</div>