无法使用Vue-Chartjs (或任何其他插件)触发beforeDraw

<template>
  <div>
    <bar-chart :chart-data="data" :options="chartOptions"></bar-chart>
  </div>
</template>

<script>
import { Bar } from 'vue-chartjs';

export default {
  extends: Bar,
  data() {
    return {
      data: {
        labels: ['Red', 'Blue', 'Yellow', 'Green', 'Purple', 'Orange'],
        datasets: [{
          label: '# of Votes',
          data: [12, 19, 3, 5, 2, 3]
        }]
      },
      chartOptions: {
        responsive: true,
        maintainAspectRatio: false,
        scales: {
          yAxes: [{
            ticks: {
              beginAtZero: true
            }
          }]
        },
        // 在这里设置beforeDraw回调函数
        beforeDraw: function(chart) {
          console.log('beforeDraw');
        }
      }
    };
  },
  mounted() {
    this.renderChart(this.data, this.chartOptions);
  }
};
</script>

mounted() {
  this.renderChart(this.data, this.chartOptions);
  this.$nextTick(() => {
    this.$refs.chart.chartObj.options.beforeDraw = function(chart) {
      console.log('beforeDraw');
    };
  });
}