javascript - 结合自动滑块和手动滑块

我想结合自动滑动和可选的手动滑动。就像滑块会自动更改照片，但有机会手动切换它(上一个/下一个按钮或小点)。
我还没有找到任何如何制作它的教程，但我找到了一个如何制作自动或手动的教程。
这是手动滑块

* {box-sizing:border-box}

/* Slideshow container */
.slideshow-container {
  max-width: 1000px;
  position: relative;
  margin: auto;
}

.mySlides {
    display: none;
}

/* Next & previous buttons */
.prev, .next {
  cursor: pointer;
  position: absolute;
  top: 50%;
  width: auto;
  margin-top: -22px;
  padding: 16px;
  color: white;
  font-weight: bold;
  font-size: 18px;
  transition: 0.6s ease;
  border-radius: 0 3px 3px 0;
}

/* 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: 13px;
  width: 13px;
  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 {
  -webkit-animation-name: fade;
  -webkit-animation-duration: 1.5s;
  animation-name: fade;
  animation-duration: 1.5s;
}

@-webkit-keyframes fade {
  from {display: block;}
  to {margin: 0;}
}

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

<div class="slideshow-container">
  <div class="mySlides fade">
    <div class="numbertext">1 / 3</div>
    <div style="width:100%;background-color: yellow;height:50px;"> </div>
    <div class="text">Caption Text</div>
  </div>

  <div class="mySlides fade">
    <div class="numbertext">2 / 3</div>
 <div style="width:100%;background-color: black;height: 50px; "> </div>
    <div class="text">Caption Two</div>
  </div>

  <div class="mySlides fade">
    <div class="numbertext">3 / 3</div>
 <div style="width:100%;background-color: blue;height: 50px;"> </div>
    <div class="text">Caption Three</div>
  </div>

  <a class="prev" onclick="plusSlides(-1)">&#10094;</a>
  <a class="next" onclick="plusSlides(1)">&#10095;</a>
</div>
<br>

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


<script type="text/javascript">
var slideIndex = 1;
showSlides(slideIndex);

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

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

function showSlides(n) {
  var i;
  var slides = document.getElementsByClassName("mySlides");
  var 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";
}
  </script>

而自动的只有js代码的变化

* {box-sizing:border-box}

/* Slideshow container */
.slideshow-container {
  max-width: 1000px;
  position: relative;
  margin: auto;
}

.mySlides {
    display: none;
}

/* Next & previous buttons */
.prev, .next {
  cursor: pointer;
  position: absolute;
  top: 50%;
  width: auto;
  margin-top: -22px;
  padding: 16px;
  color: white;
  font-weight: bold;
  font-size: 18px;
  transition: 0.6s ease;
  border-radius: 0 3px 3px 0;
}

/* 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: 13px;
  width: 13px;
  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 {
  -webkit-animation-name: fade;
  -webkit-animation-duration: 1.5s;
  animation-name: fade;
  animation-duration: 1.5s;
}

@-webkit-keyframes fade {
  from {display: block;}
  to {margin: 0;}
}

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

<div class="slideshow-container">
  <div class="mySlides fade">
    <div class="numbertext">1 / 3</div>
    <div style="width:100%;background-color: yellow;height: 50px;"> </div>
    <div class="text">Caption Text</div>
  </div>

  <div class="mySlides fade">
    <div class="numbertext">2 / 3</div>
 <div style="width:100%;background-color: black;height:50px; "> </div>
    <div class="text">Caption Two</div>
  </div>

  <div class="mySlides fade">
    <div class="numbertext">3 / 3</div>
 <div style="width:100%;background-color: blue; height: 50px;"> </div>
    <div class="text">Caption Three</div>
  </div>

  <a class="prev" onclick="plusSlides(-1)">&#10094;</a>
  <a class="next" onclick="plusSlides(1)">&#10095;</a>
</div>
<br>

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

  </section>
</article>
  <script type="text/javascript">
  var slideIndex = 0;
showSlides();

function showSlides() {
    var i;
    var slides = document.getElementsByClassName("mySlides");
    for (i = 0; i < slides.length; i++) {
        slides[i].style.display = "none";
    }
    slideIndex++;
    if (slideIndex> slides.length) {slideIndex = 1}
    slides[slideIndex-1].style.display = "block";
    setTimeout(showSlides, 2000); // Change image every 2 seconds
}
  </script>

最佳答案

添加了函数 plusSlides() 并且现在在 currentSlide() 中正确更新了 slideIndex

用这个替换你的 javascript 代码:

  var slideIndex = 0;
  var slides = document.getElementsByClassName("mySlides");

showSlides();

function showSlides() {
    var i;
    for (i = 0; i < slides.length; i++) {
        slides[i].style.display = "none";
    }
    slideIndex++;
    if (slideIndex> slides.length) {slideIndex = 1}
    slides[slideIndex-1].style.display = "block";
    setTimeout(showSlides, 5000); // Change image every 5 seconds
}

function currentSlide(no) {
    var i;
    for (i = 0; i < slides.length; i++) {
        slides[i].style.display = "none";
    }
    slideIndex = no;
    slides[no-1].style.display = "block";
}

function plusSlides(n) {
  var newslideIndex = slideIndex + n;
  if(newslideIndex < 4 && newslideIndex > 0){
     currentSlide(newslideIndex);
  }
}

关于javascript - 结合自动滑块和手动滑块，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/42698590/