SVG 笔画，CSS 动画：并非所有笔画都向同一方向移动

Question

下面的动画很简单，我是这么认为的。你会注意到其中一个笔划，而且只有一个，开始倒退。我不明白为什么会这样。

.container {
  width: 350px;
  height: 350px;
}
#path1 {
  stroke-dasharray: 170;
  animation: animate1 5s infinite linear forwards;
}

@keyframes animate1 {
  50% {
    stroke-dashoffset: -16.4%;
    stroke-dasharray: 0 87.5%;
  }
  100% {
    stroke-dashoffset: -100%;
    stroke-dasharray: 170;
  }
}

<div class="container">
    <svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px"
         width="100%" height="100%" viewBox="0 0 1000 1000" xml:space="preserve">
        <a xlink:href="#">
            <path id="path2" fill="#000" d="M173,226h400v400H173V226z"/>
            <path id="path1" fill="none" stroke="#000" d="M108,171h500v500H108V171z"/>
        </a>    
    </svg>
</div>

感谢您的帮助，感谢任何指点。

Answer 1

路径的总长度 path1 是 2000 px

如果要得到4个等间隔的4段，那么一笔画的长度就等于总长度的八分之一：2000 / 8 = 250 px

在这种情况下，写 stroke-dasharray = "250, 250"

动画是通过将 stroke-dashoffset 从 2000px 减少到零

来实现的

.container {
  width: 350px;
  height: 350px;
}
#path1 {
  stroke-dasharray: 250;
  stroke-dashoffset:2000;
  animation: animate1 5s infinite linear forwards;
}

@keyframes animate1 {
  
  100% {
    stroke-dashoffset: 0;
    stroke-dasharray: 250;
  }
}

<div class="container">
    <svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px"
         width="100%" height="100%" viewBox="0 0 1000 1000" xml:space="preserve">
        <a xlink:href="#">
            <path id="path2" fill="#000" d="M173,226h400v400H173V226z"/>
            <path id="path1" fill="none" stroke="#000" d="M108,171h500v500H108V171z"/>
        </a>    
    </svg>
</div>

SVG解决方案

<style>
.container {
  width: 350px;
  height: 350px;
}

</style>
<div class="container">
    <svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px"
         width="100%" height="100%" viewBox="0 0 1000 1000" xml:space="preserve">
        <a xlink:href="#">
            <path id="path2" fill="#000"  d="M173,226h400v400H173V226z"/>
            <path id="path1" fill="none" stroke="#000" stroke-dasharray="250,250" stroke-dashoffset="2000" d="M108,171h500v500H108V171z">
      <animate
        attributeName="stroke-dashoffset"
     from="2000"
     to="0"
     dur="5s"
     repeatCount="indefinite" />
   </path>
        </a>    
    </svg>
</div>

SVG 笔画，CSS 动画：并非所有笔画都向同一方向移动

SVG stroke, CSS animation: not all strokes moving in the same direction

css

svg

svg-animate