Question

我需要有关此幻灯片的帮助。我希望它是自动的，并且也能够手动控制。到目前为止，它在自动部分的工作还不错。但是，当我单击手动控件时，它将带我到错误的幻灯片，并且下一张或两张幻灯片的时间间隔弄乱了。如果有人对此有解决方案，请帮助。

我试图将slideIndex更改为0，但这将我带到第一张幻灯片，而不是下一张幻灯片。

  
    var slideIndex = 0;
    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"; 

      } 
  
        slideIndex++;
      if (slideIndex > slides.length) {slideIndex = 1}    
      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";
      setTimeout(showSlides, 10000); // Change image every 10 seconds
    }

   
     * {box-sizing: border-box;}
      body {font-family: Verdana, sans-serif;}
    .mySlides {display: none;}
    img {vertical-align: middle;}

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

    /* 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 {
      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 {
      -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}
    }

    /* On smaller screens, decrease text size */
    @media only screen and (max-width: 300px) {
      .text {font-size: 11px}
    }

    /* 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);
    }

    <h2>Automatic Slideshow</h2>
    <p>Change image every 10 seconds:</p>

    <div class="slideshow-container">

    <div class="mySlides fade">
      <div class="numbertext">1 / 3</div>
      <img src="img_nature_wide.jpg" style="width:100%">
      <div class="text">Caption Text</div>
    </div>

    <div class="mySlides fade">
      <div class="numbertext">2 / 3</div>
      <img src="img_snow_wide.jpg" style="width:100%">
      <div class="text">Caption Two</div>
    </div>

    <div class="mySlides fade">
      <div class="numbertext">3 / 3</div>
      <img src="img_mountains_wide.jpg" style="width:100%">
      <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>

我希望间隔是10秒，但事实证明是几秒钟。我也希望单击按钮并且它们无法正常工作时下一张/上一张幻灯片

Answer 1

我认为问题在于您正在为幻灯片自动设置超时，并且当您按下下一个或上一个按钮时，您的旧超时不会取消，因此现在您切换幻灯片时，旧超时仍会触发，然后您还设置了一个新的触发器，因此它也会在您希望的时间范围内一直触发。

我不会为每个按钮单击创建超时，而是建议使用间隔并在任何功能之外跟踪它。

当用户按下前进或后退按钮时，请取消该间隔并创建一个新间隔，这样您就不会遇到问题了，现在基本上有10个循环在同一时间向您的轮播发送垃圾邮件。 / p>

JAVASCRIPT

let slideIndex = 0;
const slideTime = 5000;
let slideInterval = setInterval(() => changeSlide(true), slideTime);

function jumpSlide(forward) {
  clearInterval(slideInterval);
  changeSlide(forward)
  slideInterval = setInterval(() => changeSlide(true), slideTime);
}

function changeSlide(forward) {
  const slides = document.getElementsByClassName('slide');
  slides[slideIndex].classList.remove('active');
  if (forward) {
   if (slideIndex + 1 > slides.length - 1) {
    slides[0].classList.add('active');
    slideIndex = 0;
  } else {
    slides[slideIndex + 1].classList.add('active');
    slideIndex ++;
  } 
  } else {
    if (slideIndex - 1 < 0) {
    slides[slides.length - 1].classList.add('active');
    slideIndex = slides.length - 1;
  } else {
    slides[slideIndex - 1].classList.add('active');
    slideIndex --;
  }
  }
}

HTML

<div class='slide-container'>
<div class='slide active'></div>
<div class='slide'></div>
<div class='slide'></div>
</div>
<button onclick='jumpSlide(false)'>last slide</button>
<button onclick='jumpSlide(true)'>next slide</button>

CSS

.slide-container{
  display: flex;
}
.slide {
  width: 50px;
  height: 50px;
  background-color: rgba(0, 0, 0, 0.25)
}
.active {
  background-color: red;
}

使用手动控件时如何固定自动幻灯片放映的时间间隔

1 个答案: