我正試圖尋找一種方法來實現一個簡單的進度圈(靜態(tài))沒有動畫。我發(fā)現的例子有非常不同的百分比偏移量，如下例所示。如果我提供50%的偏移量，那么它正好是50%(半滿)，我如何以這種方式制作進度圓？

.u-absoluteCenter {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  margin: auto;
}
.u-flexCenter {
  display: flex;
  align-items: center;
  justify-content: center;
}
.u-offscreen {
  position: absolute;
  left: -999em;
}
.demo {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  margin: auto;
  display: flex;
  align-items: center;
  justify-content: center;
}
.progress {
  transform: rotate(-90deg);
}
.progress__value {
  stroke-dasharray: 0;
  stroke-dashoffset: 0;
}
@-webkit-keyframes progress {
  from {
    stroke-dashoffset: 339.292;
  }
  to {
    stroke-dashoffset: 0;
  }
}
@keyframes progress {
  from {
    stroke-dashoffset: 339.292;
  }
  to {
    stroke-dashoffset: 0;
  }
}

<svg width="120" height="120" viewBox="0 0 120 120">
    <circle cx="60" cy="60" r="54" fill="none" stroke="#e6e6e6" stroke-width="12" />
    <circle cx="60" cy="60" r="54" fill="none" stroke="#f77a52" stroke-width="12"
        stroke-dasharray="339.292" stroke-dashoffset="339.292" />
</svg>

您可以利用SVG屬性來設置路徑長度，而不必計算它。

pathLength根據需要設置長度...比如進度條顯示100。

pathLength屬性允許作者以用戶單位指定路徑的總長度。然后，通過使用比率pathLength/(路徑長度的計算值)縮放所有距離計算，該值被用于校準瀏覽器與作者的距離計算。

pathLength="100"

然后，您也可以將stroke-dasharray設置為100，然后根據需要調整stroke-dashoffset....

::root {
  --val: 0;
}

svg {
  transform: rotate(-90deg);
}

.percent {
  stroke-dasharray: 100;
  stroke-dashoffset: calc(100 - var(--val));
}

.fifty {
  --val: 50;
}

.sixty {
  --val: 60;
}

.ninety {
  --val: 90;
}

<svg width="120" height="120" viewBox="0 0 120 120">
    <circle cx="60" cy="60" r="54" fill="none" stroke="#e6e6e6" stroke-width="12" />
    <circle class="percent fifty" cx="60" cy="60" r="54" fill="none" stroke="#f77a52" stroke-width="12" pathLength="100" />
</svg>

<svg width="120" height="120" viewBox="0 0 120 120">
    <circle cx="60" cy="60" r="54" fill="none" stroke="#e6e6e6" stroke-width="12" />
    <circle class="percent sixty" cx="60" cy="60" r="54" fill="none" stroke="#f77a52" stroke-width="12" pathLength="100" />
</svg>


<svg width="120" height="120" viewBox="0 0 120 120">
    <circle cx="60" cy="60" r="54" fill="none" stroke="#e6e6e6" stroke-width="12" />
    <circle class="percent ninety" cx="60" cy="60" r="54" fill="none" stroke="#f77a52" stroke-width="12" pathLength="100" />
</svg>

正如保利所說，路徑長度是進步圈的關鍵

一個現代的JavaScript Web組件(所有現代瀏覽器都支持JSWC)構成了一個可重用的HTML元素

<svg-progress-circle percent="30"></svg-progress-circle>
 <svg-progress-circle percent="20" color="blue"></svg-progress-circle>
 <svg-progress-circle percent="80" color="gold"></svg-progress-circle>

添加了一個用于交互式演示的范圍輸入。

Percent是元素的一個屬性，可以用如下代碼設置:

document.getElementById("Slider1").percent = <PERCENTAGE>;

如果你不想要一個灰色的虛線圓，從路徑中刪除虛線設置

我使用了一條路徑而不是重疊的圓圈，因為在其他一些設置下，幾乎相同的代碼可以創(chuàng)建餅圖。

<style>
  svg { width: 150px; background: teal }
  svg-progress-circle[percent="100"] path { stroke: green }
</style>

<svg-progress-circle percent="30"></svg-progress-circle>
<svg-progress-circle percent="20" color="blue"></svg-progress-circle>
<svg-progress-circle percent="80" color="gold"></svg-progress-circle>

<script>
  customElements.define("svg-progress-circle", class extends HTMLElement {
    connectedCallback() {
      let d = 'M5,30a25,25,0,1,1,50,0a25,25,0,1,1,-50,0'; // circle
      this.innerHTML = 
      `<input type="range" min="0" max="100" step="10" value="30"`+ // delete 2 lines
      ` oninput="this.parentNode.percent=this.value" /><br>`+ // just for demo
      
      `<svg viewBox="0 0 60 60">
       <path stroke-dasharray="10 2"   stroke-dashoffset="-19" 
             pathlength="120" d="$57dh5n5" fill="grey" stroke="lightgrey" stroke-width="5"/>
       <path stroke-dasharray="30 70" stroke-dashoffset="-25" 
             pathlength="100" d="$b7fndrt" fill="none" 
             stroke="${this.getAttribute("color")||"red"}" stroke-width="5"/>
       <text x="50%" y="57%" text-anchor="middle">30%</text></svg>`;
       
      this.style.display='inline-block';
      this.percent = this.getAttribute("percent");
    }
    set percent(val = 0) {
      this.setAttribute("percent", val);
      let dash = val + " " + (100 - val);
      this.querySelector("path+path").setAttribute('stroke-dasharray', dash);
      this.querySelector("text").innerHTML = val + "%";
      this.querySelector("input").value = val;
    }
  })
</script>