绘制空心环形

1.通过几个div拼接绘制空心环形进度条。

通过 -webkit-mask: radial-gradient(transparent 150px, #fff 150px);绘制空心圆

html:

<body>
  <div class="circle">
    <div class="circle-left"></div>
    <div class="circle-left-mask"></div>
    <div class="circle-right"></div>
    <div class="circle-right-mask"></div>
  </div>
</body>

css：

.circle {
  -webkit-mask: radial-gradient(transparent 150px, #000 150px);
  width: 400px;
  height: 400px;
  overflow: hidden;
  border-radius: 50%;
  position: relative;
}
.circle-left {
  width: 50%;
  height: 100%;
  background: rgb(234, 67, 15);
  position: absolute;
  left: 0;
  z-index: 1;
}
.circle-left-mask {
  width: 50%;
  height: 100%;
  background: #24B39B;
  transform-origin: 100% 50%;
  position: absolute;
  transition: transform 1s linear;
  left: 0;
  z-index: 2;
}
.circle-right {
  width: 50%;
  height: 100%;
  background: rgb(234, 67, 15);
  position: absolute;
  right: 0;
  z-index: 3;
}
.circle-right-mask {
  width: 50%;
  height: 100%;
  background: #24B39B;
  transition: transform 1s linear;
  transform-origin: 0% 50%;
  position: absolute;
  right: 0;
  z-index: 4;
}

js绘制度数方法

function drawing(rotate){
var right = document.getElementsByClassName('circle-right-mask')[0]
var left = document.getElementsByClassName('circle-left-mask')[0]
rotate=rotate>360?360:rotate
if(rotate<=180){
  right.style.transform = `rotate(${rotate}deg)`
}else{
  right.style.transform = `rotate(180deg)`
  setTimeout(()=>{
      left.style.transform = `rotate(${rotate - 180}deg)`
      left.style.transition = `transform ${1/180*(rotate - 180)}s linear`
      right.style.opacity = 0;
    },999)
  }
}

2.利用clip-path绘制环形

通过 -webkit-mask: radial-gradient(transparent 150px, #fff 150px);绘制空心圆

html:

  <body>
    <div class="circle">
      <div class="circle-content"></div>
      <div class="circle-content-mask"></div>
    </div>
  </body>

css:

  .circle {
    -webkit-mask: radial-gradient(transparent 150px, #000 150px);
    width: 400px;
    height: 400px;
    overflow: hidden;
    border-radius: 50%;
    position: relative;
  }
  .circle-content{
    width:100%;
    height: 100%;
    background: rgb(234, 67, 15);
    position: absolute;
    left: 0;
  }
  .circle-content-mask {
    width: 100%;
    height: 100%;
    background: #24B39B;
    left: 0;
    z-index:1;
    clip-path:polygon(50% 50%,50% 0%,50% 50%);
    -webkit-clip-path:polygon(50% 50%,50% 0%,50% 50%)
  }

通过Math.tan计算出位置，并在90、180、270、360做特殊处理

  function drawing(rotate){
    var circle = document.getElementsByClassName('circle')[0]
    var mask = document.getElementsByClassName('circle-content-mask')[0]
    var width=circle.offsetWidth
    var r = width/2
    if(rotate<90){
      var rad = rotate * Math.PI/180;
      var x = r*Math.tan(rad)+r
      mask.style=`clip-path:polygon(50% 50%,50% 0%,${x}px 0,50% 50%);-webkit-clip-path:polygon(50% 50%,50% 0%,${x}px 0,50% 50%)`
    }else if(rotate==90){
      mask.style=`clip-path:polygon(50% 50%,50% 0%,100% 0,100% 50%,50% 50%);-webkit-clip-path:polygon(50% 50%,50% 0%,100% 0,100% 50%,50% 50%)`
    }else if(rotate<180){
      var rad1 = (rotate-90) * Math.PI/180;
      var y = r*Math.tan(rad1)+r
      mask.style=`clip-path:polygon(50% 50%,50% 0%,100% 0,100% ${y}px,50% 50%);-webkit-clip-path:polygon(50% 50%,50% 0%,100% 0,100% ${y}px,50% 50%)`
    }else if(rotate==180){
      mask.style=`clip-path:polygon(50% 50%,50% 0%,100% 0,100% 100%,50% 100%,50% 50%);-webkit-clip-path:polygon(50% 50%,50% 0%,100% 0,100% 100%,50% 100%,50% 50%)`
    }else if(rotate<270){
      var rad2 = (rotate-180) * Math.PI/180;
      var x1 = r-r*Math.tan(rad2)
      mask.style=`clip-path:polygon(50% 50%,50% 0%,100% 0,100% 100%,${x1}px 100%,50% 50%);-webkit-clip-path:polygon(50% 50%,50% 0%,100% 0,100% 100%,${x1}px 100%,50% 50%)`
    }else if(rotate==270){
      mask.style=`clip-path:polygon(50% 50%,50% 0%,100% 0,100% 100%,0% 100%,0% 50%,50% 50%);-webkit-clip-path:polygon(50% 50%,50% 0%,100% 0,100% 100%,0% 100%,0% 50%,50% 50%)`
    }else if(rotate<360){
      var rad3 = (rotate-270) * Math.PI/180;
      var y2 = r-r*Math.tan(rad3)
      mask.style=`clip-path:polygon(50% 50%,50% 0%,100% 0,100% 100%,0% 100%,0% ${y2}px,50% 50%);-webkit-clip-path:polygon(50% 50%,50% 0%,100% 0,100% 100%,0% 100%,0% ${y2}px,50% 50%)`
    }else{
      mask.style=`clip-path:polygon(50% 50%,50% 0%,100% 0,100% 100%,0% 100%,0% 0%,50% 0%);-webkit-clip-path:polygon(50% 50%,50% 0%,100% 0,100% 100%,0% 100%,0% 0%,50% 0%)`
    }
    mask.style.transition = `all 1s linear`
  }

说明：

在这里插入图片描述

-#### js计算三角函数

    var sin30 = Math.sin(30 * Math.PI / 180)
    console.log(sin30);  //0.49999999999999994

    var cos60 = Math.cos(60 * Math.PI / 180)
    console.log(cos60);  //0.5000000000000001

    var tan45 = Math.tan(45 * Math.PI / 180)
    console.log(tan45);  //0.9999999999999999

css实现扇形

通过linear-gradient绘制一个左右颜色不一致的圆
设置一个伪类半圆，颜色和圆的一种颜色一致
通多动画实现
伪类旋转好多度，执行两次，如果大于180度；执行第二个动画，改变颜色，同时旋转度数执行的二次

<style>
  main{
    width: 100%;
    padding: 60px 0;
  }
  .chart{
    display: flex;
    flex-wrap: wrap;
    justify-content: space-around;
    align-items: center;
    margin-bottom: 29px;
	width:100%;
	
  }
  .chart > p{
    width: 199px;
  }
  .chart > div{
    width: 100px; 
    height: 100px;
    border-radius: 50%;
    background-color: #E8E2D6;
    background-image: linear-gradient(to right, transparent 50%, #b4a078 0);
  }
  .chart div::before{
    content: "";
    display: block;
    margin-left: 50%;
    height: 100%;
    border-radius: 0 100% 100% 0 / 0 50% 50% 0;
    background-color: inherit;
    transform-origin: 0 50%;
	/* 伪类旋转好多度，执行两次，如果大于180度；执行第二个动画，改变颜色，同时旋转度数执行的二次 */
    animation: pie-chart-spin 3s linear var(--count) forwards,
                pie-chart-bg 3s step-end forwards;
  }
  @keyframes pie-chart-spin {
    to { transform: rotate(180deg); }
  }
  @keyframes pie-chart-bg {
		to { background: var(--bgColor); }
	}

</style>
<body>
  <main>
  <!-- count:度数/360*2，bgColor：count大于1时是扇形的颜色#b4a078，小于1时是背景色#E8E2D6 -->
    <div class="chart" style='--count:1.6;--bgColor:#b4a078;---name:pie-chart-bg'>
      <div class="pie"></div>
    </div>
  </main>
</body>