vue+echarts ① The use of echarts in vue

1. Install echarts dependencies

npm install echarts --save

2. Introduce echarts globally in main.js

import * as echarts from 'echarts'
Vue.prototype.$echarts = echarts

3. Introduce echarts into the page

① Use div to install the echarts chart and place it where you want.

    <div id="echart" style="width: 100%;height:300px"></div>

To identify this component by id, it is best to give a style width and height here, otherwise it may not be loaded.

② Define the method drawCharts in methods to draw this chart.

 methods: {
    drawChart() {
      // 这里的echart同div里的id名相同即可
      const myChart = this.$echarts.init(document.getElementById("echart"));
      // option为一个设置图表格式的数组
      myChart.setOption(this.option);
    },
  },

③ Remember that the rendering of this method cannot be placed in create(), but must be placed in mounted().

  mounted() {
    this.drawChart();
  },

The option is the setting for this chart. The example option given on the official website is this thing.

Examples - Apache ECharts

 ④ Give a simple option

Just follow the examples on the official website and select the options you need.

      option: {
        title: {
          text: "测试用例",
          left: "center",
        },
        tooltip: {
          trigger: "item",
        },
        legend: {
          orient: "vertical",
          left: "left",
        },
        series: [
          {
            name: "数量",
            type: "pie",
            radius: "50%",
            data: [
              { value: 1048, name: "测试用例1" },
              { value: 735, name: "测试用例2" },
              { value: 580, name: "测试用例3" },
            ],
            emphasis: {
              itemStyle: {
                shadowBlur: 10,
                shadowOffsetX: 0,
                shadowColor: "rgba(0, 0, 0, 0.5)",
              },
            },
          },
        ],
      },

4. Page effects and complete code

① Sample effect

 ② Sample complete code

<template>
  <div>
    <div id="echart" style="width: 100%; height: 300px"></div>
  </div>
</template>

<script>
export default {
  components: {},
  data() {
    return {
      option: {
        title: {
          text: "测试用例",
          left: "center",
        },
        tooltip: {
          trigger: "item",
        },
        legend: {
          orient: "vertical",
          left: "left",
        },
        series: [
          {
            name: "数量",
            type: "pie",
            radius: "50%",
            data: [
              { value: 1048, name: "测试用例1" },
              { value: 735, name: "测试用例2" },
              { value: 580, name: "测试用例3" },
            ],
            emphasis: {
              itemStyle: {
                shadowBlur: 10,
                shadowOffsetX: 0,
                shadowColor: "rgba(0, 0, 0, 0.5)",
              },
            },
          },
        ],
      },
    };
  },
  created() {
  },
  methods: {
    drawChart() {
      const myChart = this.$echarts.init(document.getElementById("echart"));
      myChart.setOption(this.option);
    },
  },
  mounted() {
    this.drawChart();
  },
};
</script>

<style scoped lang="less">
</style>

5. Possible errors and solutions

① Error: Initialize failed: invalid dom.

 Put this.drawChart(); in create, not in mounted.

②  Error in mounted hook: "ReferenceError: echarts is not defined"

Echarts is not quoted correctly, especially check whether there is an error in the quoted section, and whether it is globally referenced in main.js.

const myChart = this.$echarts.init(document.getElementById("echart"));