我怎样才能使箭头在幻灯片上居中？在两者之间留出 100 像素的距离，并以不同的宽度留在同一个地方

Question

箭头水平和垂直居中，但我希望它们水平居中，上一个箭头和下一个箭头之间的距离为 100 像素。这样它们就不会粘在 window.

的边缘

我尝试在 div 上添加箭头，然后将它们水平和垂直居中，但无法正常工作。

(function() {

  init(); //on page load - show first slide, hidethe rest

  function init() {

    parents = document.getElementsByClassName('slideshow-container');

    for (j = 0; j < parents.length; j++) {
      var slides = parents[j].getElementsByClassName("mySlides");
      var dots = parents[j].getElementsByClassName("dot");
      slides[0].classList.add('active-slide');
      dots[0].classList.add('active');
    }
  }

  dots = document.getElementsByClassName('dot'); //dots functionality

  for (i = 0; i < dots.length; i++) {

    dots[i].onclick = function() {

      slides = this.parentNode.parentNode.getElementsByClassName("mySlides");

      for (j = 0; j < this.parentNode.children.length; j++) {
        this.parentNode.children[j].classList.remove('active');
        slides[j].classList.remove('active-slide');
        if (this.parentNode.children[j] == this) {
          index = j;
        }
      }
      this.classList.add('active');
      slides[index].classList.add('active-slide');

    }
  }
  //prev/next functionality
  links = document.querySelectorAll('.slideshow-container a');

  for (i = 0; i < links.length; i++) {
    links[i].onclick = function() {
      current = this.parentNode;

      var slides = current.getElementsByClassName("mySlides");
      var dots = current.getElementsByClassName("dot");
      curr_slide = current.getElementsByClassName('active-slide')[0];
      curr_dot = current.getElementsByClassName('active')[0];
      curr_slide.classList.remove('active-slide');
      curr_dot.classList.remove('active');
      if (this.className == 'next') {

        if (curr_slide.nextElementSibling.classList.contains('mySlides')) {
          curr_slide.nextElementSibling.classList.add('active-slide');
          curr_dot.nextElementSibling.classList.add('active');
        } else {
          slides[0].classList.add('active-slide');
          dots[0].classList.add('active');
        }

      }

      if (this.className == 'prev') {

        if (curr_slide.previousElementSibling) {
          curr_slide.previousElementSibling.classList.add('active-slide');
          curr_dot.previousElementSibling.classList.add('active');
        } else {
          slides[slides.length - 1].classList.add('active-slide');
          dots[slides.length - 1].classList.add('active');
        }

      }

    }

  }
})();

/* Slideshow container */

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


/* 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: 20px;
  width: 100%;
  text-align: center;
}

.mySlides {
  display: none;
}

.active-slide {
  display: block;
}


/* 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 {
    opacity: .4
  }
  to {
    opacity: 1
  }
}

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

<!DOCTYPE html>
<html>

<head>
  <script src="/scripts/snippet-javascript-console.min.js?v=1"></script>
</head>

<body>
  <div class="slideshow-container">
    <div class="mySlides fade">
      <div class="numbertext">1 / 4</div>
      <img src="http://www.w3schools.com/howto/img_mountains_wide.jpg" style="width:100%">
      <div class="text">Caption Text</div>
    </div>

    <div class="mySlides fade">
      <div class="numbertext">2 / 4</div>
      <img src="http://www.w3schools.com/howto/img_fjords_wide.jpg" style="width:100%">
      <div class="text">Caption Two</div>
    </div>

    <div class="mySlides fade">
      <div class="numbertext">3 / 4</div>
      <img src="http://www.w3schools.com/howto/img_nature_wide.jpg" style="width:100%">
      <div class="text">Caption Three</div>
    </div>

    <div class="mySlides fade">
      <div class="numbertext">4 / 4</div>
      <img src="http://placehold.it/1000x350" style="width:100%">
      <div class="text">Caption Four</div>
    </div>

    <a class="prev">&#10094;</a>
    <a class="next">&#10095;</a>

    <div style="text-align:center">
      <span class="dot"></span>
      <span class="dot"></span>
      <span class="dot"></span>
      <span class="dot"></span>
    </div>
  </div>
  <br>
  <div class="slideshow-container">
    <div class="mySlides fade">
      <div class="numbertext">1 / 3</div>
      <img src="http://www.w3schools.com/howto/img_mountains_wide.jpg" style="width:100%">
      <div class="text">Caption Text</div>
    </div>

    <div class="mySlides fade">
      <div class="numbertext">2 / 3</div>
      <img src="http://www.w3schools.com/howto/img_fjords_wide.jpg" style="width:100%">
      <div class="text">Caption Two</div>
    </div>

    <div class="mySlides fade">
      <div class="numbertext">3 / 3</div>
      <img src="http://www.w3schools.com/howto/img_nature_wide.jpg" style="width:100%">
      <div class="text">Caption Three</div>
    </div>

    <a class="prev">&#10094;</a>
    <a class="next">&#10095;</a>
    <div style="text-align:center">
      <span class="dot"></span>
      <span class="dot"></span>
      <span class="dot"></span>
    </div>
  </div>


  <br>
</body>

</html>

Answer 1

对此的一种解决方案可能是将箭头放在弹性盒中。使用 flexbox，您可以将 flex 项目（箭头）居中，然后在其中一个箭头上设置边距以将它们按所需宽度分隔 - 在本例中为 100px:

如果您需要在不同的旋转木马上使用不同的间距，您可以针对各个旋转木马箭头并向这些箭头添加 class 以使它们表现不同。第一个示例使用具有 flex 属性的 center 的 class 来使箭头居中，第二个示例使用具有 space-between 的 flex 属性的 between class 来推动箭头到盒子的边缘。

index = 0;
parents = document.getElementsByClassName('slideshow-container');
(function() {

  init(); //on page load - show first slide, hidethe rest

  function init() {

    // parents = document.getElementsByClassName('slideshow-container');

    for (j = 0; j < parents.length; j++) {
      var slides = parents[j].getElementsByClassName("mySlides");
      var dots = parents[j].getElementsByClassName("dot");
      slides[0].classList.add('active-slide');
      slides[0].classList.remove('fade');
      dots[0].classList.add('active');
    }
  }

  dots = document.getElementsByClassName('dot'); //dots functionality

  for (i = 0; i < dots.length; i++) {

    dots[i].onclick = function() {

      slides = this.parentNode.parentNode.getElementsByClassName("mySlides");

      for (j = 0; j < this.parentNode.children.length; j++) {
        this.parentNode.children[j].classList.remove('active');
        slides[j].classList.remove('active-slide');
        if (this.parentNode.children[j] == this) {
          index = j;
        }
      }
      this.classList.add('active');
      slides[index].classList.add('active-slide');

    }
  }


  //prev/next functionality
  links = document.querySelectorAll('.slideshow-container a');

  for (i = 0; i < links.length; i++) {
    links[i].onclick = function() {
      current = this.parentNode.parentNode.parentNode;

      var slides = current.getElementsByClassName("mySlides");
      var dots = current.getElementsByClassName("dot");
      var curr_slide = current.getElementsByClassName('active-slide')[0];
      curr_dot = current.getElementsByClassName('active')[0];
      curr_slide.classList.remove('active-slide');
      curr_dot.classList.remove('active');
      if (this.className == 'next') {

        if (curr_slide.nextElementSibling.classList.contains('mySlides')) {
          curr_slide.nextElementSibling.classList.add('active-slide');
          curr_dot.nextElementSibling.classList.add('active');
        } else {
          slides[0].classList.add('active-slide');
          dots[0].classList.add('active');
        }

      }

      if (this.className == 'prev') {

        if (curr_slide.previousElementSibling) {
          curr_slide.previousElementSibling.classList.add('active-slide');
          curr_dot.previousElementSibling.classList.add('active');
        } else {
          slides[slides.length - 1].classList.add('active-slide');
          dots[slides.length - 1].classList.add('active');
        }

      }

    }

  }
})();

/* Slideshow container */

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


/* Next & previous buttons */

.prev,
.next {
  cursor: pointer;
  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;
}

.center>.next {
  margin-left: 100px;
}


/* 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);
  color: white;
}


/* Caption text */

.text {
  color: #f2f2f2;
  font-size: 15px;
  padding: 8px 12px;
  position: absolute;
  bottom: 20px;
  width: 100%;
  text-align: center;
}

.mySlides {
  display: none;
}

.active-slide {
  display: block;
}


/* 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 {
    opacity: .4
  }
  to {
    opacity: 1
  }
}

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

.arrowWrap {
  position: absolute;
  top: calc(50% - 42px);
  width: 100%;
}

.arrowFlex {
  display: flex;
}

.center {
  justify-content: center;
  align-items: center;
}

.between {
  justify-content: space-between;
}

<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/css/bootstrap.min.css" integrity="sha384-MCw98/SFnGE8fJT3GXwEOngsV7Zt27NXFoaoApmYm81iuXoPkFOJwJ8ERdknLPMO" crossorigin="anonymous">

<div class="slideshow-container">
  <div class="mySlides">
    <div class="numbertext">1 / 4</div>
    <img src="http://www.w3schools.com/howto/img_mountains_wide.jpg" style="width:100%">
    <div class="text">Caption Text</div>
  </div>

  <div class="mySlides">
    <div class="numbertext">2 / 4</div>
    <img src="http://www.w3schools.com/howto/img_fjords_wide.jpg" style="width:100%">
    <div class="text">Caption Two</div>
  </div>

  <div class="mySlides">
    <div class="numbertext">3 / 4</div>
    <img src="http://www.w3schools.com/howto/img_nature_wide.jpg" style="width:100%">
    <div class="text">Caption Three</div>
  </div>

  <div class="mySlides">
    <div class="numbertext">4 / 4</div>
    <img src="https://picsum.photos/id/1015/1000/350" style="width:100%">
    <div class="text">Caption Four</div>
  </div>

  <div class="arrowWrap">
    <div class="arrowFlex center">
      <a class="prev">&#10094;</a>
      <a class="next">&#10095;</a>
    </div>
  </div>

  <div style="text-align:center">
    <span class="dot"></span>
    <span class="dot"></span>
    <span class="dot"></span>
    <span class="dot"></span>
  </div>
</div>

<div class="slideshow-container">
  <div class="mySlides">
    <div class="numbertext">1 / 4</div>
    <img src="http://www.w3schools.com/howto/img_mountains_wide.jpg" style="width:100%">
    <div class="text">Caption Text</div>
  </div>

  <div class="mySlides">
    <div class="numbertext">2 / 4</div>
    <img src="http://www.w3schools.com/howto/img_fjords_wide.jpg" style="width:100%">
    <div class="text">Caption Two</div>
  </div>

  <div class="mySlides">
    <div class="numbertext">3 / 4</div>
    <img src="http://www.w3schools.com/howto/img_nature_wide.jpg" style="width:100%">
    <div class="text">Caption Three</div>
  </div>

  <div class="mySlides">
    <div class="numbertext">4 / 4</div>
    <img src="https://picsum.photos/id/1015/1000/350" style="width:100%">
    <div class="text">Caption Four</div>
  </div>

  <div class="arrowWrap">
    <div class="arrowFlex between">
      <a class="prev">&#10094;</a>
      <a class="next">&#10095;</a>
    </div>
  </div>

  <div style="text-align:center">
    <span class="dot"></span>
    <span class="dot"></span>
    <span class="dot"></span>
    <span class="dot"></span>
  </div>
</div>


<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.3/umd/popper.min.js" integrity="sha384-ZMP7rVo3mIykV+2+9J3UJ46jBk0WLaUAdn689aCwoqbBJiSnjAK/l8WvCWPIPm49" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/js/bootstrap.min.js" integrity="sha384-ChfqqxuZUCnJSK3+MXmPNIyE6ZbWh2IMqE241rYiqJxyMiZ6OW/JmZQ5stwEULTy" crossorigin="anonymous"></script>

我怎样才能使箭头在幻灯片上居中？在两者之间留出 100 像素的距离，并以不同的宽度留在同一个地方

How can i center the arrows on a slideshow? leaving a100px of distance between both and staying in the same place with different widths

html

css

slideshow