Why does chartjs draw repeatedly?

import { Line } from "vue-chartjs"

export default {
  extends: Line,
  props:{
    LineChartdata:{
      type:Array,
    },
    LineChartDate:{
      type:Array,
    }
  },
  methods:{
    setChart(){
      this.renderChart({
        labels: this.LineChartDate,
        datasets: [
          {
            label: "Data One",
            backgroundColor: "-sharpF64A32",
            data: this.LineChartdata,

          }
        ]
      },this.options)
    }

  },
    mounted () { },
    watch:{
      LineChartdata(newV){
        this.setChart(newV);

      }
    }
}

example.vue

<template>
<line-chart :width="370" :height="246" :LineChartdate="LineChartdate" :LineChartdata="LineChartdata"></line-chart>
</template>
<script>
import LineChart from "./vue-chartjs/LineChart"
export default {
components: {
      LineChart
    },
},
data () {
  return {
    LineChartdata:[],
    LineChartDate:[]
  }
},
    methods:{
      getdata(){
        var user_id = this.getcookies("user_id");
          this.$http.post("http://example.com",{
            //post body
            user_id:user_id
          },{headers:{
            "datatoken":data_token,            
          }}).then((data)=>{
            //success
            this.LineChartdata=data.data
            this.Linechartdate=data.date
          })
        }

each click event passes a new array into the linechart, causing a canvas to be redrawn each time. The previous table will be displayed when the mouse is moved over the table. I tried to clear the data every time I passed the value, but it still didn"t work at that time. How can I make him overwrite the previous one every time he draws it?