vue实现一个饼状图

<template>
    <section class="chart-container">
        <el-row>                     
            <el-col :span="12">
                <div id="chartPie" style="width:100%; height:400px;"></div>
            </el-col>          
        </el-row>
    </section>
</template>
<script>
    import echarts from 'echarts'
    export default {
        data() {
            return {                                     
                chartPie: null
            }
        },
        methods: {                               
            drawPieChart() {
                this.chartPie = echarts.init(document.getElementById('chartPie'));
                this.chartPie.setOption({
                    title: {
                        text: 'Pie Chart',
                        subtext: '纯属虚构',
                        x: 'center'
                    },
                    tooltip: {
                        trigger: 'item',
                        formatter: "{a} <br/>{b} : {c} ({d}%)"
                    },
                    legend: {
                        orient: 'vertical',
                        left: 'left',
                        data: ['直接访问', '邮件营销', '联盟广告', '视频广告', '搜索引擎']
                    },
                    series: [
                        {
                            name: '访问来源',
                            type: 'pie',
                            radius: '55%',
                            center: ['50%', '60%'],
                            data: [
                                { value: 335, name: '直接访问' },
                                { value: 310, name: '邮件营销' },
                                { value: 234, name: '联盟广告' },
                                { value: 135, name: '视频广告' },
                                { value: 1548, name: '搜索引擎' }
                            ],
                            itemStyle: {
                                emphasis: {
                                    shadowBlur: 10,
                                    shadowOffsetX: 0,
                                    shadowColor: 'rgba(0, 0, 0, 0.5)'
                                }
                            }
                        }
                    ]
                });
            },
            drawCharts() {
                this.drawPieChart()
            },
        },
        mounted: function () {
            this.drawCharts()
        },
        // updated: function () {
        //     this.drawCharts()
        // }
    }
</script>
<style scoped>
    .chart-container {
        width: 100%;
        float: left;
    }
    .el-col {
        padding: 30px 20px;
    }
</style>