CSS 图像淡入淡出动画仅在第一次运行答案

【问题标题】：CSS Image Fade Animation Only Runs First TimeCSS 图像淡入淡出动画仅在第一次运行
【发布时间】：2018-06-14 21:13:38
【问题描述】：

我正在使用 CSS 制作背景图像褪色动画，它在第一次运行循环时按预期工作，但第二次在整个持续时间内卡在最后一张图像上，短暂跳转到第三张图像，然后回到最后一个。

如何更新它，使其在每个无限循环期间平稳地运行动画？

#rotate {
  width: 100%;
  height: 100%;
  position: absolute;
  bottom: 0;
  right: 0;
  margin: 0;
  padding: 0;
}

#rotate li {
  animation: func 16s linear 0s infinite;
  list-style-type: none;
  width: 100%;
  height: 100%;
  position: absolute;
  bottom: 0;
  right: 0;
  background: no-repeat 50% 30% / cover;
  opacity: 0;
}

#rotate li:nth-child(1) {
  animation-delay: 0s;
  -webkit-animation-delay: 0s;
  -moz-animation-delay: 0s;
  -o-animation-delay: 0s;
}

#rotate li:nth-child(2) {
  animation-delay: 4s;
  -webkit-animation-delay: 4s;
  -moz-animation-delay: 4s;
  -o-animation-delay: 4s;
}

#rotate li:nth-child(3) {
  animation-delay: 8s;
  -webkit-animation-delay: 8s;
  -moz-animation-delay: 8s;
  -o-animation-delay: 8s;
}

#rotate li:nth-child(4) {
  animation-delay: 12s;
  -webkit-animation-delay: 12s;
  -moz-animation-delay: 12s;
  -o-animation-delay: 12s;
}

@keyframes func {
  0%,
  100% {
    opacity: 0;
    animation-timing-function: ease-in;
  }
  5%,
  90% {
    opacity: 1;
  }
}

<ul id="rotate">
  <li style="background-image: url('https://dummyimage.com/600x400/000/fff&text=one')"></li>
  <li style="background-image: url('https://dummyimage.com/600x400/000/fff&text=two')"></li>
  <li style="background-image: url('https://dummyimage.com/600x400/000/fff&text=three');"></li>
  <li style="background-image:url('https://dummyimage.com/600x400/000/fff&text=four')"></li>
</ul>

以及指向 Codepen 示例的链接：https://codepen.io/erinpearson/pen/YvxVRM?editors=1100

【问题讨论】：

标签： html css css-animations

【解决方案1】：

更改@keyframes 中的不透明度。

#rotate {
  width: 100%;
  height: 100%;
  position: absolute;
  bottom: 0;
  right: 0;
  margin: 0;
  padding: 0;
}

#rotate li {
  animation: func 16s linear 0s infinite;
  list-style-type: none;
  width: 100%;
  height: 100%;
  position: absolute;
  bottom: 0;
  right: 0;
  background: no-repeat 50% 30% / cover;
  opacity: 0;
}

#rotate li:nth-child(1) {
  animation-delay: 0s;
  -webkit-animation-delay: 0s;
  -moz-animation-delay: 0s;
  -o-animation-delay: 0s;
}

#rotate li:nth-child(2) {
  animation-delay: 4s;
  -webkit-animation-delay: 4s;
  -moz-animation-delay: 4s;
  -o-animation-delay: 4s;
}

#rotate li:nth-child(3) {
  animation-delay: 8s;
  -webkit-animation-delay: 8s;
  -moz-animation-delay: 8s;
  -o-animation-delay: 8s;
}

#rotate li:nth-child(4) {
  animation-delay: 12s;
  -webkit-animation-delay: 12s;
  -moz-animation-delay: 12s;
  -o-animation-delay: 12s;
}

@keyframes func {
  0% {
    opacity: 0;
  }
  6% {
    opacity: 1;
  }
  24% {
    opacity: 1;
  }
  30% {
    opacity: 0;
  }
  100% {
    opacity: 0;
  }
}

<ul id="rotate">
  <li style="background-image: url('https://dummyimage.com/600x400/000/fff&text=one')"></li>
  <li style="background-image: url('https://dummyimage.com/600x400/000/fff&text=two')"></li>
  <li style="
  background-image: url('https://dummyimage.com/600x400/000/fff&text=three');"></li>
  <li style="background-image: url('https://dummyimage.com/600x400/000/fff&text=four')"></li>
</ul>

【讨论】：