javascript - 如何使图像 slider 响应拇指滑动

Question

您好，我使用的是基本的 W3 幻灯片布局，但它不太适合我网站的移动版本。

我非常努力地搜索以找到解决此问题的方法，但它总是下载一些插件以使其工作或对滑动 react 不佳的东西

$('.slider').on('touchstart', function(event) {
  const xClick = event.originalEvent.touches[0].pageX;
  
  $(this).one('touchmove', function(event) {
    const xMove = event.originalEvent.touches[0].pageX;
    const sensitivityInPx = 5;

    if (Math.floor(xClick - xMove) > sensitivityInPx) {
      $(this).slider('next');
    } 
    else if (Math.floor(xClick - xMove) < -sensitivityInPx) {
      $(this).slider('prev');
    }
  });
  
  $(this).on('touchend', function() {
    $(this).off('touchmove');
  });
});

let slideIndex = 1;
showSlides(slideIndex);

function plusSlides(n) {
  showSlides(slideIndex += n);
}

function currentSlide(n) {
  showSlides(slideIndex = n);
}

function showSlides(n) {
  let i;
  let slides = document.getElementsByClassName("mySlides");
  let dots = document.getElementsByClassName("dot");
  
  if (n > slides.length) {
    slideIndex = 1
  }
  
  if (n < 1) {
    slideIndex = slides.length
  }
  
  for (i = 0; i < slides.length; i++) {
    slides[i].style.display = "none";
  }
  
  for (i = 0; i < dots.length; i++) {
    dots[i].className = dots[i].className.replace(" active", "");
  }
  
  slides[slideIndex - 1].style.display = "block";
  dots[slideIndex - 1].className += " active";
}

* {
  box-sizing: border-box
}

html,
body {
  width: 100%;
  height: 100%;
  margin: 0;
}

body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
}

.mySlides {
  display: none
}

img {
  vertical-align: middle;
}

/* Slideshow container */

.slideshow-container {
  padding: 10px;
  max-width: 1000px;
  position: relative;
  margin: auto;
  -webkit-overflow-scrolling: touch;
}

/* Next & previous buttons */

.prev,
.next {
  cursor: pointer;
  position: absolute;
  top: 50%;
  width: auto;
  padding: 16px;
  margin-top: -22px;
  color: white;
  font-weight: bold;
  font-size: 18px;
  transition: 0.6s ease;
  border-radius: 0 3px 3px 0;
  user-select: none;
}

/* Position the "next button" to the right */

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

/* On hover, add a black background color with a little bit see-through */

.prev:hover,
.next:hover {
  background-color: rgba(0, 0, 0, 0.8);
}

/* Caption text */

.text {
  color: #f2f2f2;
  font-size: 15px;
  padding: 8px 12px;
  position: absolute;
  bottom: 8px;
  width: 100%;
  text-align: center;
}

/* Number text (1/3 etc) */

.numbertext {
  color: #f2f2f2;
  font-size: 12px;
  padding: 8px 12px;
  position: absolute;
  top: 0;
}

/* The dots/bullets/indicators */

.dot {
  cursor: pointer;
  height: 15px;
  width: 15px;
  margin: 0 2px;
  background-color: #bbb;
  border-radius: 50%;
  display: inline-block;
  transition: background-color 0.6s ease;
}

.active,
.dot:hover {
  background-color: #717171;
}

/* Fading animation */

.fade {
  animation-name: fade;
  animation-duration: 1.5s;
}

@keyframes fade {
  from {
    opacity: .4
  }
  to {
    opacity: 1
  }
}

/* On smaller screens, decrease text size */

@media only screen and (max-width: 300px) {
  .prev,
  .next,
  .text {
    font-size: 11px
  }
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div id="slider" class="slideshow-container">
  <!-- images -->
  <div class="mySlides fade">
    <!-- <div class="numbertext">1 / 3</div> -->
    <img src="http://upload.wikimedia.org/wikipedia/commons/7/73/Lion_waiting_in_Namibia.jpg" style="width:100%">
    <div class="text">Caption Text</div>
  </div>

  <div class="mySlides fade">
    <img src="http://upload.wikimedia.org/wikipedia/commons/7/73/Lion_waiting_in_Namibia.jpg" style="width:100%">
  </div>

  <div class="mySlides fade">
    <img src="http://upload.wikimedia.org/wikipedia/commons/7/73/Lion_waiting_in_Namibia.jpg" style="width:100%">
  </div>

  <div class="mySlides fade">
    <img src="http://upload.wikimedia.org/wikipedia/commons/7/73/Lion_waiting_in_Namibia.jpg" style="width:100%">
  </div>

  <a class="prev" onclick="plusSlides(-1)">❮</a>
  <a class="next" onclick="plusSlides(1)">❯</a>
</div>
<br>

<div style="text-align:center">
  <!-- dots-->
  <span class="dot" onclick="currentSlide(1)"></span>
  <span class="dot" onclick="currentSlide(2)"></span>
  <span class="dot" onclick="currentSlide(3)"></span>
  <span class="dot" onclick="currentSlide(4)"></span>
</div>

Answer 1

尽管这不是纯 Js，而是一种不同的方法

我发现 flickity.js 和 css 对移动设备很好，它只是像 jquery 一样的 2 个 ajax 调用

https://flickity.metafizzy.co/api.html

<script src="//cdnjs.cloudflare.com/ajax/libs/flickity/1.0.0/flickity.pkgd.js"></script>

<link rel="stylesheet" href="//cdnjs.cloudflare.com/ajax/libs/flickity/1.0.0/flickity.css">

HTML

<div class="carousel">
  <div class="carousel-cell"></div>
  <div class="carousel-cell"></div>
  <div class="carousel-cell"></div>
  <div class="carousel-cell"></div>
  <div class="carousel-cell"></div>
  <div class="carousel-cell"></div>
  <div class="carousel-cell"></div>
  <div class="carousel-cell"></div>
</div>

CSS

/* external css: flickity.css */

* { box-sizing: border-box; }

body { font-family: sans-serif; }

.carousel {
  background: #FAFAFA;
}

.carousel-cell {
  width: 28%;
  height: 200px;
  margin-right: 10px;
  background: #8C8;
  border-radius: 5px;
  counter-increment: carousel-cell;
}

/* cell number */
.carousel-cell:before {
  display: block;
  text-align: center;
  content: counter(carousel-cell);
  line-height: 200px;
  font-size: 80px;
  color: white;
}

.button {
  font-size: 22px;
}

.button-group {
  margin-bottom: 20px;
}

Js

// external js: flickity.pkgd.js

var flkty = new Flickity( '.carousel', {
  groupCells: true
});

var buttonGroup = document.querySelector('.button-group');
var buttons = buttonGroup.querySelectorAll('.button');
buttons = fizzyUIUtils.makeArray( buttons );

buttonGroup.addEventListener( 'click', function( event ) {
  // filter for button clicks
  if ( !matchesSelector( event.target, '.button' ) ) {
    return;
  }
  var index = buttons.indexOf( event.target );
  flkty.selectCell( index );
});