vuex数据状态持久化问题

window.addEventListener("beforeunload", () => {
    	sessionStorage.setItem("store", JSON.stringify(this.$store.state))
    })

if(sessionStorage.getItem("store")) {
    	this.$store.replaceState(Object.assign({}, this.$store.state, JSON.parse(sessionStorage.getItem('store'))))
    }

created() {
    // 页面加载时，读取sessionStorage中的状态信息
    if(sessionStorage.getItem("store")) {
      this.$store.replaceState(Object.assign({}, this.$store.state, JSON.parse(sessionStorage.getItem('store'))))
    }
    // 在页面刷新时，将vuex中的信息保存到sessionStorage里
    window.addEventListener("beforeunload", () => {
      sessionStorage.setItem("store", JSON.stringify(this.$store.state))
    })
  },

cnpm i --save vuex-persistedstate

import createPersistedState from 'vuex-persistedstate'

plugins: [createPersistedState()]

import Vue from 'vue'
	import Vuex from 'vuex'
	import createPersistedState from 'vuex-persistedstate'
	Vue.use(Vuex)
	export default new Vuex.Store({
	  plugins: [createPersistedState({
	    storage: window.sessionStorage, // 默认位置是 localStorage
	    reducer: (state) => {
	      return {
	        // 默认是全部缓存，在这里可以设置需要缓存的状态
	        token: state.token
	      }
	    }
	  })],
	  state: {
	    token: ''
	  },
	  mutations: {
	  },
  }