JQuery：画像スライダの現在のdivを削除

Question

画像間で切り替える画像スライダが2つあり、最初にスライダに項目を追加し、2番目の項目はスライダから現在の画像を削除しますが機能しません。

[アイテムを削除]ボタンをクリックすると、現在のアイテムがスライダから削除されます。

var slideIndex = 1; 
 
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"; 
 
    } 
 
    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"; 
 
} 
 

 
$('#NewsItem').click(function() { 
 
    
 
    var maindiv = $("<div class='mySlides fade'>") 
 
       .append($("<div class='numbertext'>4/4</div>")) 
 
       .append($("<img src='4.jpg' style='width:100%;height:650px' />")) 
 
       .append($("<div class='text'>Caption Four</div>")); 
 

 
    $('.slideshow-container').append(maindiv); 
 
    $('.footer').append($("<span class='dot' onclick='currentSlide(4)'></span>")); 
 
});

* {box-sizing:border-box} 
 
body {font-family: Verdana,sans-serif;margin:0} 
 
.mySlides {display:none} 
 

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

 
/* 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; 
 
} 
 

 
/* 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: 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 { 
 
    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} 
 
} 
 

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

<script src="https://code.jquery.com/jquery-3.2.1.min.js"></script> 
 

 
<button id="NewsItem">Add Item</button> 
 
    <button id="RemoveItem">remove Item</button> 
 

 
<div class="slideshow-container"> 
 

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

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

 
    <div class="mySlides fade"> 
 
     <div class="numbertext">3/3</div> 
 
     <img src="3.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" class="footer"> 
 
     <span class="dot" onclick="currentSlide(1)"></span> 
 
     <span class="dot" onclick="currentSlide(2)"></span> 
 
     <span class="dot" onclick="currentSlide(3)"></span> 
 
    </div>

Answer 1

私はアクティブなスライドを削除するようにコードを編集しました。しかし、スライドに使用した方法が適切でないため、リストが使い尽くされるとエラーが発生する可能性があります。インデックスをdata-attrと設定し、現在のスライドを追跡する必要があります。ボタンのクリックでインデックスを取得する必要があります。スライドのインデックスは動的スライドにも作成され、自動インクリメントされることもあります。

var slideIndex = 1; 
 
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"; 
 
    } 
 
    for (i = 0; i < dots.length; i++) { 
 
     dots[i].className = dots[i].className.replace(" active", ""); 
 
    } 
 
    slides[slideIndex - 1].style.display = "block"; 
 
    slides[slideIndex - 1].className += " active"; 
 
    slides[slideIndex - 1].id=slideIndex; 
 
    dots[slideIndex - 1].className += " active"; 
 
} 
 
$('#RemoveItem').click(function() { 
 
$(".active").remove(); 
 
}); 
 
$('#NewsItem').click(function() { 
 
    
 
    var maindiv = $("<div class='mySlides fade'>") 
 
       .append($("<div class='numbertext'>4/4</div>")) 
 
       .append($("<img src='4.jpg' style='width:100%;height:650px' />")) 
 
       .append($("<div class='text'>Caption Four</div>")); 
 

 
    $('.slideshow-container').append(maindiv); 
 
    $('.footer').append($("<span class='dot' onclick='currentSlide(4)'></span>")); 
 
});

* {box-sizing:border-box} 
 
body {font-family: Verdana,sans-serif;margin:0} 
 
.mySlides {display:none} 
 

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

 
/* 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; 
 
} 
 

 
/* 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); 
 
} 
 
.slideshow-container{ 
 
margin-top:20px; 
 
} 
 
/* 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 { 
 
    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} 
 
} 
 

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

<script src="https://code.jquery.com/jquery-3.2.1.min.js"></script> 
 

 
<button id="NewsItem">Add Item</button> 
 
    <button id="RemoveItem">remove Item</button> 
 

 
<div class="slideshow-container"> 
 

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

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

 
    <div class="mySlides fade"> 
 
     <div class="numbertext">3/3</div> 
 
     <img src="3.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" class="footer"> 
 
     <span class="dot" onclick="currentSlide(1)"></span> 
 
     <span class="dot" onclick="currentSlide(2)"></span> 
 
     <span class="dot" onclick="currentSlide(3)"></span> 
 
    </div>