微信小程序集成ECharts图表库：安装、配置与懒加载详解

git clone https://github.com/ecomfe/echarts-for-weixin.git

git checkout v2.0.0

{
  "usingComponents": {
    "ec-canvas": "/activity/components/ec-canvas/ec-canvas"
  }
}

<view class="ec-container">
  <ec-canvas canvas-id="echart-pie" ec="{{ec}}"></ec-canvas>
</view>

.ec-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;

  width: 100vw;
  height: 100vh;
}

ec-canvas {
  width: 100%;
  height: 100%;
}

import * as echarts from '../../components/ec-canvas/echarts'

function initChart(canvas, width, height, dpr) {
  const chart = echarts.init(canvas, null, {
    width: width,
    height: height,
    devicePixelRatio: dpr
  });
  canvas.setChart(chart);

  var option = {
    backgroundColor: "#ffffff",
    series: [{
      label: {
        normal: {
          fontSize: 14
        }
      },
      type: 'pie',
      center: ['50%', '50%'],
      radius: ['20%', '40%'],
      data: [{
        value: 55,
        name: '北京'
      }, {
        value: 20,
        name: '武汉'
      }, {
        value: 10,
        name: '杭州'
      }, {
        value: 20,
        name: '广州'
      }, {
        value: 38,
        name: '上海'
      }]
    }]
  };
  chart.setOption(option);

  return chart;
}

Page({
  data: {
    ec: {
      onInit: initChart
    }
  }
})

<view class="ec-container">
  <ec-canvas id="lazy-echart-pie" canvas-id="lazy-canvas-pie" ec="{{lazyEc}}"></ec-canvas>
</view>

Page({
  data: {
    lazyEc: {
      lazyLoad: true
    }
  }
})

this.lazyComponent = this.selectComponent('#lazy-echart-pie')

this.lazyComponent.init((canvas, width, height, dpr) => {
  const chart = echarts.init(canvas, null, {
    width: width,
    height: height,
    devicePixelRatio: dpr
  });
  canvas.setChart(chart);

  this.lazyChart = chart;

  var option = {
    ...
  };
  chart.setOption(option);

  return chart;
});

this.lazyChart.dispose();