使用Canvas绘制移动端百分比仪表盘

<!doctype html> 
<html lang="en"> 
<head> 
  <meta charset="utf-8"> 
  <meta http-equiv="Pragma" content="no-cache"> 
  <meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=no"/> 
  <meta name="format-detection" content="telephone=no"/> 
  <meta name="apple-mobile-web-app-capable" content="yes"/> 
  <meta name="apple-mobile-web-app-status-bar-style" content="black"/> 
  <title>canvas绘制简易百分比仪表盘dashboard（建议最好用于移动端）</title> 
  <style type="text/css"> 
    div{margin:1rem;background:#eee;padding:.3rem; position:relative } 
    div canvas{background:#cacaca; 
      -webkit-transform: rotateZ(-270deg); 
      transform:rotateZ(-270deg); 
      -webkit-animation:ani01 1s ease 0s both; 
      animation:ani01 1s ease 0s both; 
    } 
 
    @-webkit-keyframes ani01 { 
      0%{ 
        -webkit-transform:scale(.5,.5) rotateZ(-270deg); 
        transform:scale(.5,.5) rotateZ(-270deg); 
      } 
      100%{ 
        -webkit-transform:scale(1,1) rotateZ(-90deg); 
        transform:scale(1,1) rotateZ(-90deg); 
      } 
    } 
    @keyframes ani01 { 
      0%{ 
        -webkit-transform:scale(.5,.5) rotateZ(-270deg); 
        transform:scale(.5,.5) rotateZ(-270deg); 
      } 
      100%{ 
        -webkit-transform:scale(1,1) rotateZ(-90deg); 
        transform:scale(1,1) rotateZ(-90deg); 
      } 
    } 
  </style> 
</head> 
<body> 
 
<div> 
  <canvas id="myCanvas1" data-percent="80"> 
    您的浏览器不支持canvas标签。 
  </canvas> 
  <span style="display:block;position:absolute;top:.94rem;left:.3rem;width:2rem;text-align:center;font-size:.5rem;font-family:microsoft Yahei" id="dushu" >0</span> 
</div> 
 
<script type="text/javascript" src="../js/flexible.js"></script> 
<script type="text/javascript"> 
  var pper=0; 
  var pper_interal; 
  var dushu=document.getElementById('dushu'); 
 
  var aaa=drawCanvanPercent('myCanvas1','rem',2,'#0e9cfa',0.2,'#fff'); 
 
  function drawCanvanPercent(ele_id,dw,cir_r,cir_color,line_w,fill_color){ 
    if(dw=="rem"){ 
      cir_r=cir_r*(window.screen.width/10); 
      line_w=line_w*(window.screen.width/10); 
    } 
    var canvas = document.getElementById(ele_id); 
    var circle = { 
      r : cir_r/2,   //圆的半径 
      per : canvas.getAttribute('data-percent'),   //百分比分子 
      color : cir_color,   //圆的颜色 
      lineWidth : line_w   //圆的颜色 
    }; 
    canvas.width=canvas.height=circle.r*2; 
    canvas.style.borderRadius="50%"; 
    if(canvas.getContext){ 
      var ctx2 = canvas.getContext("2d"); 
      ctx2.fillStyle = fill_color; 
      ctx2.arc(circle.r, circle.r, circle.r-circle.lineWidth/2, 0, Math.PI*2, false); 
      ctx2.fill(); 
      var ctx = canvas.getContext("2d"); 
      pper_interal= setInterval(function () { 
        drawMove(ctx,circle); 
      }, 10); 
    } 
  } 
 
  function drawMove(ctx,circle){ 
    if(pper>=circle.per){ 
      pper=circle.per; 
      clearTimeout(pper_interal); 
    }else{ 
      pper++; 
    } 
    dushu.innerText=pper+'%'; 
    ctx.beginPath(); 
    ctx.strokeStyle = circle.color; 
    ctx.lineWidth=circle.lineWidth; 
    ctx.arc(circle.r, circle.r, circle.r, 0, Math.PI*(pper/100)*360/180, false); 
    ctx.stroke(); 
  } 
  </script> 
 
</body> 
</html>