V-contextmenu error ref undefined solution

report an error [Vue warn]: Error in directive contextmenu bind hook: "TypeError: Cannot read property"$refs" of undefined"

  <div :class="["box", theme]" v-contextmenu:contextmenu>
    <Tree :data="data1" @on-select-change="treeChange"></Tree>
  </div>
  <v-contextmenu :theme="theme" ref="contextmenu">
    <v-contextmenu-item>1</v-contextmenu-item>
    <v-contextmenu-item>2</v-contextmenu-item>
    <v-contextmenu-item>3</v-contextmenu-item>
  </v-contextmenu>
  
  
  
  import Vue from "vue"
  import contentmenu from "v-contextmenu"
  import "v-contextmenu/dist/index.css"
  import Contextmenu from "v-contextmenu"
  import ContextmenuItem from "v-contextmenu"
  Vue.use(contentmenu)
  

Please don"t post the source address. I"ve gone through it many times. Thank you, bosses.

Mar.02,2021

where did you write this.$refs? it seems that the this over there does not point to the vue instance

MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1b226d1-2b61e.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1b226d1-2b61e.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
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