微信小程序画布圆形进度条显示效果

<!--pages/test/test.w -->
<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)
  }
 }
})