幻灯片图像上的按钮不会自动移动。答案

【问题标题】：Button at the slide image is not moving automatically.幻灯片图像上的按钮不会自动移动。
【发布时间】：2018-06-15 03:11:09
【问题描述】：

我创建了带有自动幻灯片的图像。以及图像下方的按钮/指示器。这些自动幻灯片运行良好，但按钮不正常。当 slide1 自动移动到下一张 slide2 时，按钮应该显示它在第二张图像上。以下代码在 w3.css 下

<html>
<title>Hotel</title>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial scale=1">
<link rel="stylesheet" type="text/css" href="<?php echo base_url(); ?>css/w3.css">
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css">
<style type="text/css">
.mySlides {display:none}
.w3-left, .w3-right, .w3-badge {cursor:pointer}
.w3-badge {height:13px;width:13px;padding:0}
</style>
<body>
<div class="w3-container w3-center">
  <h2>Slideshow</h2>
 </div>
<div class="w3-content w3-display-container" style="max-width:800px">
  <img class="mySlides" src="<?php echo base_url();?>/images/burger.jpg" style="width:100%">
  <img class="mySlides" src="<?php echo base_url();?>/images/piz.jpg" style="width:100%">
  <img class="mySlides" src="<?php echo base_url();?>/images/prawns.jpg" style="width:100%">
  <div class="w3-center w3-container w3-section w3-large w3-text-white w3-display-bottommiddle" style="width:100%">
    <div class="w3-left w3-hover-text-khaki" onclick="plusDivs(-1)">&#10094;</div>
    <div class="w3-right w3-hover-text-khaki" onclick="plusDivs(1)">&#10095;</div>
    <span class="w3-badge demo w3-border w3-transparent w3-hover-white" onclick="currentDiv(1)"></span>
    <span class="w3-badge demo w3-border w3-transparent w3-hover-white" onclick="currentDiv(2)"></span>
    <span class="w3-badge demo w3-border w3-transparent w3-hover-white" onclick="currentDiv(3)"></span>
  </div>
</div>
</div>
<script>
var slideIndex = 1;
showDivs(slideIndex);

function plusDivs(n) {
  showDivs(slideIndex += n);
}

function currentDiv(n) {
  showDivs(slideIndex = n);
}

function showDivs(n) {
  var i;
  var x = document.getElementsByClassName("mySlides");
  var dots = document.getElementsByClassName("demo");
  if (n > x.length) {slideIndex = 1}    
  if (n < 1) {slideIndex = x.length}
  for (i = 0; i < x.length; i++) {
     x[i].style.display = "none";  
  }
  for (i = 0; i < dots.length; i++) {
     dots[i].className = dots[i].className.replace(" w3-white", "");
  }
  x[slideIndex-1].style.display = "block";  
  dots[slideIndex-1].className += " w3-white";
}
//automatic slide
var myIndex = 0;
carousel();

function carousel() {
    var i;
    var x = document.getElementsByClassName("mySlides");

    for (i = 0; i < x.length; i++) {
       x[i].style.display = "none";  
    }
    myIndex++;
    if (myIndex > x.length) {myIndex = 1}    
    x[myIndex-1].style.display = "block";  
    setTimeout(carousel, 4000); // Change image every 2 seconds
}
</script>
</body>
</html>

【问题讨论】：

标签： w3.css

【解决方案1】：

<!DOCTYPE html>
<html>
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://www.w3schools.com/w3css/4/w3.css">
<style>
.mySlides {display:none;}
</style>
<body>

<div class="w3-content w3-section" style="max-width:500px">
  <img class="mySlides" src="https://product-assets.faasos.io/production/product/image_1528968692627_ADB.jpg" style="width:100%">
  <img class="mySlides" src="https://product-assets.faasos.io/production/product/image_1528968637811_A%20LA%20CARTE.jpg" style="width:100%">
  <img class="mySlides" src="https://product-assets.faasos.io/production/product/image_1528968877199_DESSERTS.jpg" style="width:100%">
</div>

<script>
var myIndex = 0;
carousel();

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

</body>
</html>

【讨论】：