微信小程序画布圆形进度条显示效果

<!--pages/test/test.wxml-->
<canvas style="width: 300px; height: 200px;" canvas-id="canvasid"></canvas>

// pages/test/test.js
var context = new wx.createCanvasContext('canvasid', this);
var strat_num = 1, end_num = 20;
var sAngle = 1.5 * Math.PI, eAngle = 0;
Page({
 onReady: function () {
 this.canvas()
 },
 canvas:function(){
 var that=this;
 if (strat_num <= end_num){
 console.log('strat_num:', strat_num)
 eAngle = strat_num * 2 * Math.PI / end_num + 1.5 * Math.PI;
 setTimeout(function () {
 context.setStrokeStyle("#00ff00")
 context.setLineWidth(2)
 context.fillText(strat_num * 5 <= 100?strat_num * 5:100, 95, 95)
 context.arc(100, 100, 60, sAngle, eAngle, false)
 context.stroke()
 context.draw()
 that.canvas()
 strat_num++
 },200)
 } else {
 console.log('strat_num_end:', strat_num)
 }
 }
})