web canvas — 实现环形进度条

web canvas -- 实现环形进度条 var canvas = document.getElementById('myCanvas'); var ctx = canvas.getContext("2d"); var drawCircle = (o) => { ctx.beginPath(); ctx.lineWidth = o.lineWidth ctx.arc(o.x, o.y, o.radius, 1.5 * Math.PI, (1.5 + (o.angle * 2)) * Math.PI,false); ctx.lineCap = 'round'; ctx....