vue中使用echarts遇到的Error in v-on handler: "TypeError: Cannot read property 'getAttribute' of null"

<div v-if="showType==1" id="lineChart" style="width: 100%;height:100%;"></div>

<div v-if="showType==2" id="columnChart" style="width: 600px;height:400px;"></div>

loadEcharts(type) {
    var that = this;
    if (type == 1) {
        that.showType = 1;
        // 基于准备好的dom，初始化echarts实例
        var myChart = echarts.init(document.getElementById(‘lineChart‘), ‘light‘);
        var option = {
            title: {
                text: ‘未来一周气温变化‘,
                subtext: ‘纯属虚构‘
            },
            tooltip: {
                trigger: ‘axis‘
            },
            legend: {
                data: [‘最高气温‘, ‘最低气温‘]
            },
            toolbox: {
                show: true,
                feature: {
                    dataZoom: {
                        yAxisIndex: ‘none‘
                    },
                    dataView: { readOnly: false },
                    magicType: { type: [‘line‘, ‘bar‘] },
                    restore: {},
                    saveAsImage: {}
                }
            },
            xAxis: {
                type: ‘category‘,
                boundaryGap: false,
                data: [‘周一‘, ‘周二‘, ‘周三‘, ‘周四‘, ‘周五‘, ‘周六‘, ‘周日‘]
            },
            yAxis: {
                type: ‘value‘,
                axisLabel: {
                    formatter: ‘{value} °C‘
                }
            },
            series: [
                {
                    name: ‘最高气温‘,
                    type: ‘line‘,
                    data: [11, 11, 15, 13, 12, 13, 10],
                    markPoint: {
                        data: [
                            { type: ‘max‘, name: ‘最大值‘ },
                            { type: ‘min‘, name: ‘最小值‘ }
                        ]
                    },
                    markLine: {
                        data: [
                            { type: ‘average‘, name: ‘平均值‘ }
                        ]
                    }
                },
                {
                    name: ‘最低气温‘,
                    type: ‘line‘,
                    data: [1, -2, 2, 5, 3, 2, 0],
                    markPoint: {
                        data: [
                            { name: ‘周最低‘, value: -2, xAxis: 1, yAxis: -1.5 }
                        ]
                    },
                    markLine: {
                        data: [
                            { type: ‘average‘, name: ‘平均值‘ },
                            [{
                                symbol: ‘none‘,
                                x: ‘90%‘,
                                yAxis: ‘max‘
                            }, {
                                symbol: ‘circle‘,
                                label: {
                                    position: ‘start‘,
                                    formatter: ‘最大值‘
                                },
                                type: ‘max‘,
                                name: ‘最高点‘
                            }]
                        ]
                    }
                }
            ]
        };
        // 使用刚指定的配置项和数据显示图表。
        myChart.setOption(option);
    } else {
        that.showType = 2;
        // 基于准备好的dom，初始化echarts实例
        var myChart = echarts.init(document.getElementById(‘columnChart‘), ‘light‘);
        // 指定图表的配置项和数据
        var option = {
            title: {
                text: ‘世界人口总量‘,
                subtext: ‘数据来自网络‘
            },
            tooltip: {
                trigger: ‘axis‘,
                axisPointer: {
                    type: ‘shadow‘
                }
            },
            grid: {
                left: ‘3%‘,
                right: ‘4%‘,
                bottom: ‘3%‘,
                containLabel: true
            },
            xAxis: {
                type: ‘value‘,
                boundaryGap: [0, 0.01]
            },
            yAxis: {
                type: ‘category‘,
                data: [‘巴西‘, ‘印尼‘, ‘美国‘, ‘印度‘, ‘中国‘, ‘世界人口(万)‘]
            },
            series: [
                {
                    type: ‘bar‘,
                    data: [18203, 23489, 29034, 104970, 131744, 630230]
                }
            ]
        };


        // 使用刚指定的配置项和数据显示图表。
        myChart.setOption(option);
    }


},

mounted() {
    this.$nextTick(() => {
      this.drawLine();
    });
  }