canvas绘制进度圆环


<html xmlns="http://www.w3.org/1999/xhtml">
<style>
#cavas{
    width: 100%;
}
style>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
        <meta name="viewport" content="width=device-width,initial-scale=1,minimum-scale=1,maximum-scale=1,user-scalable=no" />
        <title>title>
    head>

    <body>
        <canvas id = "cavas" height="232">  
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        canvas>  
    body>

html>
/**
 * 绘制进度圆环
 */
var canvas = document.getElementById("cavas"),
    ctx = canvas.getContext("2d"),
    circleValue = {
        x : 150,
        y : 120,
        radius : 86,
        startAngle : 0,
        endAngle : 2 * Math.PI,
        anticlockwise : false
    };

drowArc(ctx,0.8);
function drowArc(ctx,percent){

    //打底 圆环 绘制
    ctx.lineWidth = 11;
    ctx.beginPath(); 
    var grd = ctx.createRadialGradient(circleValue.x, circleValue.y, 72, circleValue.x, circleValue.y, 93);
    grd.addColorStop(0,"#e9eae9");
    grd.addColorStop("0.8","#fefefe");
    grd.addColorStop("1","#e9eae9");
    ctx.strokeStyle = grd;
    ctx.arc(circleValue.x, circleValue.y, circleValue.radius, circleValue.startAngle, circleValue.endAngle, circleValue.anticlockwise);
    ctx.closePath(); 
    ctx.stroke();

    //展示进度圆环绘制
    ctx.lineWidth = 11;
    ctx.beginPath();
    var linear = ctx.createLinearGradient(100,100,200,100);
    linear.addColorStop(0,'#ffc26b');
    linear.addColorStop(0.5,'#ff9a5f');
    linear.addColorStop(1,'#ff8157');
    ctx.strokeStyle = linear;
    ctx.arc(circleValue.x, circleValue.y, circleValue.radius, circleValue.startAngle, circleValue.endAngle*percent, circleValue.anticlockwise);
    ctx.stroke();

    //进度起点圆角
    ctx.beginPath();
    ctx.fillStyle = '#ff8157';
    ctx.arc(circleValue.x + circleValue.radius, circleValue.y - 1, 5.5, circleValue.startAngle, circleValue.endAngle, circleValue.anticlockwise);
    ctx.closePath();
    ctx.fill();

    //终点圆角
    ctx.lineWidth = 3.5;
    ctx.beginPath();
    ctx.shadowOffsetX = 0;
    ctx.shadowOffsetY = 0;
    ctx.shadowBlur = 6;
    ctx.shadowColor = '#ff7854';
    ctx.fillStyle = '#ff7854';
    ctx.strokeStyle = '#fff';
    //计算终点的坐标
    var getX = circleValue.x + circleValue.radius * Math.cos(2 * percent * Math.PI),
        getY = circleValue.y + circleValue.radius * Math.sin(2 * percent * Math.PI);
    ctx.arc(getX , getY, 9, circleValue.startAngle, circleValue.endAngle, circleValue.anticlockwise);
    ctx.closePath();
    ctx.fill();
    ctx.stroke();
}

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