css - 错误的关键帧动画

Question

从昨天早上开始，我一直在努力实现看起来像这样的东西:

.signature-stroke{
  stroke-dasharray: 1700;
  stroke-dashoffset: 1700;
  stroke-width: 6;
  animation: writing 2.2s linear forwards;
}


@keyframes writing {
  0% {
    stroke-dashoffset: 1700;
  }
  45% {
    stroke-width: 5;
  }
  90% {
    stroke-dashoffset: 0;
  }
  100% {
    stroke-dashoffset: 0;
    stroke-width: 15;
  }
}

<svg 
xmlns="http://www.w3.org/2000/svg"
width="419px" height="259px"
viewBox="0 0 419 259"
>
    <defs>
    <clipPath id="clipmask">
        <path
      d="M397.37,76.381c-8.974-5.228-13.697-15.834-16.289-15.834
        c-10.234,0-8.95,3.233-14.357,3.233c-5.408,0-6.776-3.257-10.946-3.257c-8.079,0-14.854,9.382-16.744,9.382
        s9.392-19.012,9.392-22.872c0-5.354-4.993-6.743-5.765-6.743c-0.384,0-38.497,36.477-68.792,77.331
        c-30.672,41.363-53.528,87.11-53.528,87.11s60.356-146.88,77.346-146.88c-0.097-4.332-3.712-8.515-4.915-8.515
        c-1.204,0-12.647,13.511-16.695,13.511c-2.579,0.156-4.17,2.856-7.665,2.856c-12.016,0-36.991,12.886-39.754,12.886
        s16.946-22.446,1.538-22.446c-9.923,0-35.131,22.435-35.131,22.435s6.618-17.243,14.679-33.837
        c8.451-17.398,16.979-31.299,18.283-33.277c2.018-3.361-1.366-7.071-3.66-7.071c-1.898,0-10.389,13.3-22.744,29.04
        c-18.53,23.604-43.023,53.441-45.148,53.441c-3.543,0,3.063-8.038-1.724-8.038s-34.692,24.231-34.692,24.231
        s51.531-50.008,34.414-50.008c-14.429,0-32.956,4.339-52.128,11.714c0.025,0.348,0.045,0.705,0.068,1.056l-0.531-0.871
        c0.154-0.06,0.309-0.126,0.463-0.185C98.653,13.166,76.952-0.1,44.464-0.1C8.716-0.1,3.823,8.233,3.823,8.233
        s-6.237,6.919,1.958,6.919c-7.817,0,11.38-9.144,37.834-9.144c20.818,0,51.589,0.545,52.93,61.067l-1.133,0.489l0,0.001
        C48.538,87.229,0.293,123.92,0.293,158.951c0,22.949,14.123,28.245,21.625,28.245c25.835,0,80.986-40.162,80.986-105.7
        c0-3.941-0.084-7.699-0.246-11.289c-0.48,0.184-0.958,0.378-1.438,0.567l1.437-0.597c0,0.01,0.001,0.02,0.001,0.03
        c14.294-5.477,28.942-8.771,42.988-8.771c7.556,0-38.633,47.908-38.633,47.908s-5.211,9.118,0.261,9.118
        c9.379,0,35.432-30.481,41.163-30.481s0.612,5.254,0.612,5.254s-3.428,4.599,1.087,4.599c7.949,0.321,52.805-57.511,52.805-57.511
        l-20.604,48.399c0,0-3.929,9.443,1.18,9.443c6.263,0,32.273-29.65,41.089-29.65c3.511,0-4.914,12.56-4.914,12.56
        s-4.993,7.957,2.809,7.957c7.801,0,36.275-17.631,52.112-17.631c0.081,0-24.937,33.123-44.005,76.622
        c-20.308,46.326-35.227,102.967-35.227,102.967s-2.002,7.388,2.794,7.388c6.233,0.063,8.304-5.986,8.304-7.799
        c41.945-95.346,113.029-186.61,128.238-191.517c-3.647,5.992-5.472,21.363-5.472,21.363s-0.261,3.908,3.647,3.908
        s10.161-12.245,12.245-12.245s-0.447,2.271,2.271,2.271c4.583-0.254,3.521-7.42,7.421-7.42c3.899,0,6.322,4.832,11.663,4.832
        c5.342,0,5.172-2.628,10.259-2.628c9.75,0,2.204,16.193,41.458,16.193C412.93,83.523,408.947,83.124,397.37,76.381z
         M21.013,179.856c-8.636,0-14.304-8.246-14.304-18.928c0-24.325,42.091-67.734,89.77-88.21l0.005,0.025l0.094-0.039
        C95.809,141.202,41.799,179.856,21.013,179.856z"/>

<path 
      d="M157.326,16.264c-3.229,0-7.774,4.546-7.774,7.775c0,3.229,2.618,5.847,5.848,5.847
         c3.229,0,11.372-3.483,11.372-8.932C166.771,15.476,160.556,16.264,157.326,16.264z"/>
    </clipPath>
    </defs>

    <g 
  class="stroke" 
  clip-path="url(#clipmask)"
  stroke-linejoin="miter"
  stroke-miterlimit="5"
    >
  <path
    class="signature-stroke"
    fill="none"
    stroke="#B247B3"
    d="M1.645,12.002c0,0,16.003-8.467,42.266-8.467
    S99.995,9.407,99.995,71.25s-45.844,113.042-78.79,113.042c-14.247,0-17.564-14.147-17.564-26.453
    C3.641,133,63,57.333,153.667,57.333C161,57.333,106,111,111.333,111c0,0,33.091-26.667,40.333-26.667s-4.521,9.581,0,9.581
    s72-84.247,72-84.247S181.109,92,186.333,92s26.334-29.333,43-29.333c6.549,0-9.334,20-4.334,20c0,0,31.667-13.89,49.667-13.89
    c5.712,0,9.647-13.443,16.333-13.443c-22,21.333-103.333,197-90.667,196.333c5.883,0,107.333-201.333,143.333-204.333
    c0,0-13.771,31.667-9.333,31.667s9.705-11.667,14-11.667s4.332-2.523,7.666-2.523s4.579,3.966,10.667,3.966
    s4.441-3.966,11.333-3.966s13.084,20.525,40.209,20.525"/>

  <path 
    class="signature-dot"
    fill="#B247B3" 
    d="M157.326,16.264c-3.229,0-7.774,4.546-7.774,7.775c0,3.229,2.618,5.847,5.848,5.847 c3.229,0,11.372-3.483,11.372-8.932C166.771,15.476,160.556,16.264,157.326,16.264z">
  </path>
    </g>
</svg>   

所以我用 Illustrator 创建了一个 svg 代码，一些简单的东西，只会说“嘿”。

.hey {
  stroke-width: 6;
  stroke: black;
  stroke-dasharray: 10;
    /* here you can see the dashes are wrong. there is no space between them. the dashes are around and not along the path! */ 
}
 .hey2 {
  stroke-width: 6;
  stroke: black;
  stroke-dasharray: 3900;
  stroke-dashoffset: 3900;
  animation: dash 15s linear forwards;
} 

/* you can see the animation is wrong and the animation goes around the path... */

@keyframes dash {
  to {
    stroke-dashoffset: 0;
  }
}

<svg class="hey" version="1.1" id="Calque_1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px"
     viewBox="0 0 1280 1024" style="enable-background:new 0 0 1280 1024;" xml:space="preserve">
<g>
    <g>
        <path d="M149.4,259.7c33.9-20.7,65.8-44.7,95.1-71.5c23.7-21.7,54.6-49.6,47.6-85.3c-3-15.2-13.3-27.1-28.4-31.1
            c-14.8-3.9-34.2-3.4-43.9,10.2c-4.6,6.5-6.9,14.4-8.7,22c-2.3,9.8-4,19.8-5.1,29.8c-2.4,20.7-2.5,41.7-1.7,62.5
            c1.8,47.4,8.3,94.8,4.5,142.3c1-0.1,2-0.3,2.9-0.4c-4.6-21.4-2.3-44.1,6.5-64.2c4.1-9.5,9.7-19.4,17.2-26.6
            c9.9-9.4,22.1-6.7,29.8,3.8c6.6,9,7.6,20.7,11.2,31c2.5,7.1,6.5,15.4,14.3,17.8c8.8,2.8,16.9-3.6,23-9.2c7.3-6.7,14-14.1,20-22
            c14-18.4,24.1-39.5,29.7-61.8c0.2-0.8-0.2-1.7-1-1.8c-14.4-3.2-25.2,9.2-30.4,21.2c-5,11.7-6,26.2-0.8,38.1
            c15.3,35.1,58.4-2.1,72.4-19.3c11.7-14.4,20-31.3,24.2-49.4c-1-0.1-2-0.3-2.9-0.4c-0.8,7.2-0.7,14.5,0.5,21.7
            c1,6.2,2.5,14.5,6.2,19.7c2.7,3.7,6.7,2.9,10,0.5c6.1-4.4,11.8-9.9,17.3-15.1c19.4-18.7,36-45.3,27.2-73.1
            c-0.5-1.6-2.9-1.3-2.9,0.4c-1.2,93.5-2.4,187.5-17,280.1c-2,12.8-4.3,25.5-6.8,38.1c-2,10.2-4.3,23.7-15.2,28.1
            c0.6,0.3,1.2,0.7,1.8,1c-13.3-39.6-11.6-83.3,3.3-122.2c7.5-19.5,18.3-37.8,32-53.5c15.6-17.8,34.9-31.9,54.8-44.5
            c18.4-11.6,39.7-22.8,47.8-44.3c0.7-1.8-2.2-2.6-2.9-0.8c-8,21.2-29.9,32-47.9,43.5c-19.8,12.6-39,26.8-54.4,44.6
            c-26.5,30.4-41.8,69.8-44.4,109.9c-1.5,23.1,1.5,46.3,8.8,68.2c0.2,0.7,1.1,1.4,1.8,1c7-2.8,11-8.7,13.6-15.6
            c3.7-10.1,5.1-21.2,7-31.7c4.3-23.6,7.6-47.4,10.2-71.3c5.4-48.9,7.7-98,9-147.1c0.7-27.8,1.1-55.6,1.5-83.5c-1,0.1-2,0.3-2.9,0.4
            c7.5,23.9-4.8,47.6-21,64.7c-3.9,4.1-8.1,8-12.3,11.8c-2.1,1.9-4.3,3.7-6.5,5.6c-0.9,0.7-1.7,1.5-2.6,2.2c-1.4,1.9-3,2.2-4.8,0.8
            c-1.7,0.1-2.7-0.6-3-2.1c-3.2-4.6-4.2-12.8-5-18.2c-0.9-6.4-0.9-12.9-0.2-19.3c0.2-1.7-2.6-2-2.9-0.4
            c-6.3,27.4-22.4,52.1-45.1,68.7c-11.1,8.1-28.8,18.9-40.9,7c-8.4-8.3-9.2-22.6-7.1-33.6c2.6-13.4,13.4-32.6,29.8-29
            c-0.3-0.6-0.7-1.2-1-1.8c-5.3,21.1-14.6,40.9-27.5,58.5c-6.4,8.7-13.6,16.8-21.5,24.1c-4.9,4.5-11.5,10.2-18.7,8.8
            c-5.8-1.2-9.5-6.5-11.8-11.5c-7.3-15.8-7-42.3-28.2-47.3c-18.5-4.4-31.2,20.2-37.2,33.8c-9.2,20.9-11.5,44.2-6.8,66.5
            c0.4,1.7,2.8,1.2,2.9-0.4c6.1-76.6-15.3-154.2,1.3-230.2c1.7-7.9,3.6-16.2,8-23.1c5.4-8.6,13.9-11.9,23.8-12.3
            c17.9-0.7,35.5,5.6,42.2,23.4c13,34.5-17.4,64.1-40.2,85.4c-30.4,28.4-63.6,53.6-99.1,75.3C146.2,258.1,147.7,260.7,149.4,259.7
            L149.4,259.7z"/>
    </g>
</g>
</svg>
<svg class="hey2" version="1.1" id="Calque_1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px"
     viewBox="0 0 1280 1024" style="enable-background:new 0 0 1280 1024;" xml:space="preserve">
<g>
    <g>
        <path d="M149.4,259.7c33.9-20.7,65.8-44.7,95.1-71.5c23.7-21.7,54.6-49.6,47.6-85.3c-3-15.2-13.3-27.1-28.4-31.1
            c-14.8-3.9-34.2-3.4-43.9,10.2c-4.6,6.5-6.9,14.4-8.7,22c-2.3,9.8-4,19.8-5.1,29.8c-2.4,20.7-2.5,41.7-1.7,62.5
            c1.8,47.4,8.3,94.8,4.5,142.3c1-0.1,2-0.3,2.9-0.4c-4.6-21.4-2.3-44.1,6.5-64.2c4.1-9.5,9.7-19.4,17.2-26.6
            c9.9-9.4,22.1-6.7,29.8,3.8c6.6,9,7.6,20.7,11.2,31c2.5,7.1,6.5,15.4,14.3,17.8c8.8,2.8,16.9-3.6,23-9.2c7.3-6.7,14-14.1,20-22
            c14-18.4,24.1-39.5,29.7-61.8c0.2-0.8-0.2-1.7-1-1.8c-14.4-3.2-25.2,9.2-30.4,21.2c-5,11.7-6,26.2-0.8,38.1
            c15.3,35.1,58.4-2.1,72.4-19.3c11.7-14.4,20-31.3,24.2-49.4c-1-0.1-2-0.3-2.9-0.4c-0.8,7.2-0.7,14.5,0.5,21.7
            c1,6.2,2.5,14.5,6.2,19.7c2.7,3.7,6.7,2.9,10,0.5c6.1-4.4,11.8-9.9,17.3-15.1c19.4-18.7,36-45.3,27.2-73.1
            c-0.5-1.6-2.9-1.3-2.9,0.4c-1.2,93.5-2.4,187.5-17,280.1c-2,12.8-4.3,25.5-6.8,38.1c-2,10.2-4.3,23.7-15.2,28.1
            c0.6,0.3,1.2,0.7,1.8,1c-13.3-39.6-11.6-83.3,3.3-122.2c7.5-19.5,18.3-37.8,32-53.5c15.6-17.8,34.9-31.9,54.8-44.5
            c18.4-11.6,39.7-22.8,47.8-44.3c0.7-1.8-2.2-2.6-2.9-0.8c-8,21.2-29.9,32-47.9,43.5c-19.8,12.6-39,26.8-54.4,44.6
            c-26.5,30.4-41.8,69.8-44.4,109.9c-1.5,23.1,1.5,46.3,8.8,68.2c0.2,0.7,1.1,1.4,1.8,1c7-2.8,11-8.7,13.6-15.6
            c3.7-10.1,5.1-21.2,7-31.7c4.3-23.6,7.6-47.4,10.2-71.3c5.4-48.9,7.7-98,9-147.1c0.7-27.8,1.1-55.6,1.5-83.5c-1,0.1-2,0.3-2.9,0.4
            c7.5,23.9-4.8,47.6-21,64.7c-3.9,4.1-8.1,8-12.3,11.8c-2.1,1.9-4.3,3.7-6.5,5.6c-0.9,0.7-1.7,1.5-2.6,2.2c-1.4,1.9-3,2.2-4.8,0.8
            c-1.7,0.1-2.7-0.6-3-2.1c-3.2-4.6-4.2-12.8-5-18.2c-0.9-6.4-0.9-12.9-0.2-19.3c0.2-1.7-2.6-2-2.9-0.4
            c-6.3,27.4-22.4,52.1-45.1,68.7c-11.1,8.1-28.8,18.9-40.9,7c-8.4-8.3-9.2-22.6-7.1-33.6c2.6-13.4,13.4-32.6,29.8-29
            c-0.3-0.6-0.7-1.2-1-1.8c-5.3,21.1-14.6,40.9-27.5,58.5c-6.4,8.7-13.6,16.8-21.5,24.1c-4.9,4.5-11.5,10.2-18.7,8.8
            c-5.8-1.2-9.5-6.5-11.8-11.5c-7.3-15.8-7-42.3-28.2-47.3c-18.5-4.4-31.2,20.2-37.2,33.8c-9.2,20.9-11.5,44.2-6.8,66.5
            c0.4,1.7,2.8,1.2,2.9-0.4c6.1-76.6-15.3-154.2,1.3-230.2c1.7-7.9,3.6-16.2,8-23.1c5.4-8.6,13.9-11.9,23.8-12.3
            c17.9-0.7,35.5,5.6,42.2,23.4c13,34.5-17.4,64.1-40.2,85.4c-30.4,28.4-63.6,53.6-99.1,75.3C146.2,258.1,147.7,260.7,149.4,259.7
            L149.4,259.7z"/>
    </g>
</g>
</svg>

根据我对本教程的理解 https://css-tricks.com/svg-line-animation-works/ , 我不得不在我的 svg 中添加一个笔画，它会是虚线。

这一步对我来说是一团糟，因为每次 svg 都没有正确划线。如您所见，有一条线仍然可见。破折号在周围而不是沿着路径。因此，当我激活关键帧时，动画是一条围绕 svg 的线，这很奇怪 - 绝对不是我想要的。

我是第一次在这里发帖，刚开始学写代码，如有不妥之处还请见谅。

非常感谢!

Answer 1

这是我所做的:

1. 我已经通过删除一半来编辑您的路径。现在它只是一条线，之前是一条封闭的路径。
2. 我已经重新计算了 stroke-dasharray 和 stroke-dashoffset 的值。为此，我使用了 hey.getTotalLength()

希望这就是您所需要的。

.hey {
  stroke-width: 6;
  stroke: black;
}
 #hey {
  stroke-width: 6;
  stroke: black;
  stroke-dasharray: 1896.892333984375;
  stroke-dashoffset: 1896.892333984375;
  animation: dash 15s linear forwards;
} 

/* you can see the animation is wrong and the animation goes around the path... */

@keyframes dash {
  to {
    stroke-dashoffset: 0;
  }
}

<svg class="hey" version="1.1" id="Calque_1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px"
     viewBox="0 0 1280 1024" style="enable-background:new 0 0 1280 1024;" xml:space="preserve">
<g>
    <g>
        <path id="hey"
              fill="none"d="M149.4,259.7c33.9-20.7,65.8-44.7,95.1-71.5c23.7-21.7,54.6-49.6,47.6-85.3c-3-15.2-13.3-27.1-28.4-31.1
            c-14.8-3.9-34.2-3.4-43.9,10.2c-4.6,6.5-6.9,14.4-8.7,22c-2.3,9.8-4,19.8-5.1,29.8c-2.4,20.7-2.5,41.7-1.7,62.5
            c1.8,47.4,8.3,94.8,4.5,142.3c1-0.1,2-0.3,2.9-0.4c-4.6-21.4-2.3-44.1,6.5-64.2c4.1-9.5,9.7-19.4,17.2-26.6
            c9.9-9.4,22.1-6.7,29.8,3.8c6.6,9,7.6,20.7,11.2,31c2.5,7.1,6.5,15.4,14.3,17.8c8.8,2.8,16.9-3.6,23-9.2c7.3-6.7,14-14.1,20-22
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