如何在图像之间添加微妙的过渡？

Question

我创建了this 问题并且能够让我的滑块工作。现在我需要在图像之间添加平滑过渡。我在 CSS 中尝试了过渡/动画，但效果很奇怪 - 图像之间存在黑色。我认为过渡属性需要添加到 JS 中。

现状 - 由于图像突然变化，存在明显差异 期望 - 我希望图像可以轻松进出。

非常感谢这方面的任何帮助！

附： -> 在这里复制粘贴代码以方便使用：

let line = document.getElementById("line");

line.addEventListener("input", function(event){
  setNewImage(event.target.value);
});

function setNewImage(value){
  // console.log(value);
  let currentImage = document.getElementsByClassName("playing");
  let removedImage = currentImage[0].classList.remove("playing");
  let imageToAdd = "image"+value;
  // console.log(imageToAdd);
  
  let getElToAdd = document.getElementsByClassName(imageToAdd);
  
  // console.log(getElToAdd);
  
  let newEl = getElToAdd[0];
  
 newEl.classList.add("playing");
}

.container {
  display: flex;
  justify-content: center;
  flex-direction: column;
  background-color: lavendar;
  width: 400px;
  height: 300px;
}

.image-container {
  width: 380px;
  height: 280px;
/*   background-color: pink; */
}

.scrollbar {
/*   padding: 0 5px 5px 0; */
}
.scrollbar input {
  width: 380px;
}

ul li {
  list-style: none;
}

.image {
  width: 380px;
  height: 260px;
  display: none;
}

.playing {
  display: block;
}
.image1 {
  background: url('http://placekitten.com/380/260') no-repeat;
}

.image2 {
  background: url('http://placekitten.com/378/260') no-repeat;
}

.image3 {
  background: url('http://placekitten.com/380/259') no-repeat;
}

.image4 {
  background: url('http://placekitten.com/379/260') no-repeat;
}

.image5 {
  background: url('http://placekitten.com/383/260') no-repeat;
}

.image6 {
  background: url('http://placekitten.com/380/261') no-repeat;
}

<div class="container">
  <div class="image-container">
    <ul>
      <li><img class="playing image image1" /></li>
      <li><img class="image image2" /></li>
      <li ><img class="image image3" /></li>
      <li><img class="image image4" /></img></li>
      <li><img class="image image5" /></li>
      <li><img class="image image6"/></li>
    </ul>
  </div>
  <div class="scrollbar">
    <input id="line" type="range" min=1 max =6 />
  </div>
</div>

Answer 1

使用opacity 而不是display 可以添加过渡，并使您的元素位置绝对以使它们彼此之上：

let line = document.getElementById("line");

line.addEventListener("input", function(event) {
  setNewImage(event.target.value);
});

function setNewImage(value) {
  // console.log(value);
  let currentImage = document.getElementsByClassName("playing");
  let removedImage = currentImage[0].classList.remove("playing");
  let imageToAdd = "image" + value;
  // console.log(imageToAdd);

  let getElToAdd = document.getElementsByClassName(imageToAdd);

  // console.log(getElToAdd);

  let newEl = getElToAdd[0];

  newEl.classList.add("playing");
}

.container {
  display: flex;
  justify-content: center;
  flex-direction: column;
  background-color: lavendar;
  width: 400px;
  height: 300px;
}

.image-container {
  width: 380px;
  height: 280px;
}


.scrollbar input {
  width: 380px;
}

ul {
 position:relative; /*make them relative to ul not li*/
 margin:0;
 padding:0;
}
/* added this*/
ul li .image {
  position:absolute;
  top:0;
  left:0;
}
/**/
ul li {
  list-style: none;
}

.image {
  width: 380px;
  height: 260px;
  opacity: 0;
  transition:1s all;
}

.playing {
  opacity:1;
}

.image1 {
  background: url('http://placekitten.com/380/260') no-repeat;
}

.image2 {
  background: url('http://placekitten.com/378/260') no-repeat;
}

.image3 {
  background: url('http://placekitten.com/380/259') no-repeat;
}

.image4 {
  background: url('http://placekitten.com/379/260') no-repeat;
}

.image5 {
  background: url('http://placekitten.com/383/260') no-repeat;
}

.image6 {
  background: url('http://placekitten.com/380/261') no-repeat;
}

<div class="container">
  <div class="image-container">
    <ul>
      <li>
        <div class="playing image image1"></div>
      </li>
      <li>
        <div class="image image2"></div>
      </li>
      <li>
        <div class="image image3"></div>
      </li>
      <li>
        <div class="image image4"></div>
      </li>
      <li>
        <div class="image image5"></div>
      </li>
      <li>
        <div class="image image6"></div>
      </li>
    </ul>
  </div>
  <div class="scrollbar">
    <input id="line" type="range" min=1 max=6>
  </div>
</div>