echarts 解決“There is a chart instance already initialized on the dom”問題

解決辦法：

在重復調用之前先銷毀之前的echarts

 if (this.chart != null && this.chart != "" && this.chart != undefined) {
        this.chart.dispose(); //銷毀
  }
 this.chart = this.$echarts.init(this.$el);
 this.chart.setOption(option);