微信小程序中使用ECharts 异步加载数据实现图表功能

<view class="container">
 <ec-canvas id="mychart-dom-bar" canvas-id="mychart-bar" ec="{{ ec }}"></ec-canvas>
</view>

import * as echarts from '../../ec-canvas/echarts';
var barec = null
Page({
 onShareAppMessage: function (res) {
 return {
 title: 'ECharts 可以在微信小程序中使用啦！',
 path: '/pages/index/index',
 success: function () { },
 fail: function () { }
 }
 },
 data: {
 ec: {
 onInit: function (canvas, width, height) {
 barec = echarts.init(canvas, null, {
 width: width,
 height: height
 });
 canvas.setChart(barec);
 return barec;
 }
 }
 },
 onReady() {
 setTimeout(this.getData, 500);
 },
//getData方法里发送ajax
 getData(){
 wx.showLoading({
 title: '加载中...',
 })
 wx.request({
 url: 'http://192.168.3.81/heart.php',
 herder:{
 "content-type":"json"
 },
 success:function(res){
 console.log(res);
 var data = res.data.info;
 console.log(data);
 barec.setOption({
 grid: {
 left: '3%',
 right: '7%',
 bottom: '3%',
 containLabel: true
 },
 tooltip: {
 // trigger: 'axis',
 showDelay: 0,
 formatter: function (params) {
 if (params.value.length > 1) {
 return params.seriesName + ' :<br/>'
 + params.value[0] + 'm '
 + params.value[1] + 'm ';
 }
 else {
 return params.seriesName + ' :<br/>'
 + params.name + ' : '
 + params.value + 'm ';
 }
 },
 axisPointer: {
 show: true,
 type: 'cross',
 lineStyle: {
 type: 'dashed',
 width: 1
 }
 }
 },
 legend: {
 data: ["学生"],
 left: 'center'
 },
 xAxis: [
 {
 type: 'value',
 scale: true,
 axisLabel: {
 formatter: '{value} m'
 },
 splitLine: {
 show: false
 }
 }
 ],
 yAxis: [
 {
 type: 'value',
 scale: true,
 axisLabel: {
 formatter: '{value} m'
 },
 splitLine: {
 show: false
 }
 }
 ],
 series: [{
 name: '学生',
 // symbolSize: 20,
 data:data,
 type: 'scatter',
 markArea: {
 silent: true,
 itemStyle: {
 normal: {
 color: 'transparent',
 borderWidth: 1,
 borderType: 'dashed'
 }
 },
 data: [[{
 name: '教室',
 xAxis: '0',
 yAxis: '0'
 }, {
 xAxis: '20',
 yAxis: '20'
 }]]
 },
 markPoint: {
 // data: [
 // { type: 'max', name: '最大值' },
 // { type: 'min', name: '最小值' }
 // ]
 },
 markLine: {
 lineStyle: {
 normal: {
 type: 'solid'
 }
 },
 // data: [
 // { type: 'average', name: '平均值' },
 // { xAxis: 160 }
 // ]
 }
 }]
 })
 wx.hideLoading(); 
 },
 fail: function (res) { },
 complete: function (res) { },
 })
 }
});