javascript - 我怎样才能修复幻灯片使点自动工作

Question

我尝试显示自动幻灯片。图片正在更改，但下面的点不起作用。当我点击任何点时，它会起作用，但我希望每个点在幻灯片切换时同时变成白色。

这是html文件:

<div class="slideshow-container">
            <div class="mySlides fade">
                <img src="images/laptop.png" class="welcome__img" style="width:100%">
            </div>
            <div class="mySlides fade">
                <img src="images/laptop.png" class="welcome__img" style="width:100%">
            </div>
            <div class="mySlides fade">
                <img src="images/laptop.png" class="welcome__img" style="width:100%">
            </div>
            <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>
        </div>

这是CSS:

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

/* Hide the images by default */
.mySlides {
    display: none;
}

.dot {
  cursor: pointer;
  height: 10px;
  width: 10px;
  margin: 0 2px;
  background-color: $grey;
  border-radius: 50%;
  display: inline-block;
  transition: background-color 0.6s ease;
}

.active, .dot:hover {
  background-color: $white;
}

/* 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}
}

和 JS:

var slideIndex = 0;
showSlides();

function showSlides() {
    var i;
    var slides = document.getElementsByClassName("mySlides");
    var dots = document.getElementsByClassName("dot");
    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"; 


   for (i = 0; i < dots.length; i++) {
      dots[i].className = dots[i].className.replace(" active", "");
  }
    setTimeout(showSlides, 2000); // Change image every 2 seconds
}

setTimeout 可以正常工作，但点不会改变它们的填充颜色。

Answer 1

将其放入 showSlides() 的 for 循环中。

if (i === slideIndex) {
  dots[i].className = "dot active";
} else {
  dots[i].className = "dot";
}