javascript - 如何修复正在声明但其值从未被读取的 Javascript slider 按钮功能？

Question

我正在制作一个 HTML、CSS、Javascript slider ，底部带有按钮来指示哪张幻灯片处于事件状态。这些点应该将 1,2,3 的值传递回 currentSlide 函数，但它似乎不起作用。

//HTML
<div id="slider">
    <div class="slide active">
         <p>slide1</p>
    </div>

    <div class="slide">
         <p>slide2</p>
    </div>

    <div class="slide">
         <p>slide3</p>
    </div>

    <div>
        <span class="dot" onclick="currentSlide(1)"></span>
        <span class="dot" onclick="currentSlide(2)"></span>
        <span class="dot" onclick="currentSlide(3)"></span>
    </div>
</div>

//CSS


//Javascript
var slideIndex = 1;
showSlides(slideIndex);

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

function showSlides(n) {
  var i;
  var slides = document.getElementsByClassName("slide");
  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";
}

如有任何反馈，我们将不胜感激。

Answer 1

当 slideIndex 实际上是一个有效值时，您从未将它设置为 n - 请参阅下面的代码片段中的更改。

//Javascript
var slideIndex = 1;
showSlides(slideIndex);

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

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

  if (n > slides.length) {slideIndex = 1}    
  else if (n < 1) {slideIndex = slides.length}
  else { slideIndex = n }
  
  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";
}

<div id="slider">
    <div class="slide active">
         <p>slide1</p>
    </div>

    <div class="slide">
         <p>slide2</p>
    </div>

    <div class="slide">
         <p>slide3</p>
    </div>

    <div>
        <span class="dot" onclick="currentSlide(1)">1</span>
        <span class="dot" onclick="currentSlide(2)">2</span>
        <span class="dot" onclick="currentSlide(3)">3</span>
    </div>
</div>