page {
 width: 100%;
 height: 100%;
 background-color: #fff;
}
 
.circle-box {
 text-align: center;
 margin-top: 10vw;
}

.circle {
 position: absolute;
 left: 0;
 right: 0;
 margin: auto;
}

.draw_btn {
 width: 35vw;
 position: absolute;
 top: 33vw;
 right: 0;
 left: 0;
 margin: auto;
 border: 1px #000 solid;
 border-radius: 5vw;
}

<view class="wrap">
 <view class="circle-box">
 <canvas class="circle" style="z-index: -99; width:200px; height:200px;" canvas-id="canvasCircle">
 </canvas>
 <canvas class="circle" style="width:200px; height:200px;" canvas-id="canvasArcCir">
 </canvas>
 <view class="draw_btn">
 <view>80分</view>
 <view>(滿分100分)</view>
 </view>
 </view>
</view>

// pages/circle/circle.js
//獲取應用實例
const app = getApp()
var ctx = wx.createCanvasContext('canvasArcCir');
Page({

 /**
 * 頁面的初始數(shù)據(jù)
 */
 data: {

 },
 drawCircle: function() {
 function drawArc(s, e) {
 ctx.setFillStyle('white');
 ctx.clearRect(0, 0, 200, 200);
 ctx.draw();
 var x = 100,
 y = 100,
 radius = 96;
 ctx.setLineWidth(5);
 ctx.setStrokeStyle('#d81e06');
 ctx.setLineCap('round');
 ctx.beginPath();
 //圓心的 x,y坐標,radius半徑 s:起始弧度，單位弧度（在3點鐘方向） e:終止弧度,:false弧度的方向是否是逆時針
 ctx.arc(x, y, radius, s, e, false);
 ctx.stroke()
 ctx.draw()
 }
 var step = 70,
 startAngle = 1.5 * Math.PI,
 endAngle = 0,
 n = 100,
 endAngle = step * 2 * Math.PI / n + 1.5 * Math.PI;
 drawArc(startAngle, endAngle);

 },
 /**
 * 生命周期函數(shù)--監(jiān)聽頁面加載
 */
 onLoad: function(options) {
 //調(diào)用畫圓的方法
 this.drawCircle()
 },
 /**
 * 生命周期函數(shù)--監(jiān)聽頁面初次渲染完成
 */
 onReady: function() {
 //創(chuàng)建并返回繪圖上下文context對象。
 var cxt_arc = wx.createCanvasContext('canvasCircle');
 cxt_arc.setLineWidth(6);
 cxt_arc.setStrokeStyle('#eaeaea');
 cxt_arc.setLineCap('round');
 cxt_arc.beginPath();
 cxt_arc.arc(100, 100, 96, 0, 2 * Math.PI, false);
 cxt_arc.stroke();
 cxt_arc.draw();
 },
})