vuex状态持久化，vuex-persistedstate

保存在vuex里的数据，页面刷新就会丢失，可以用vuex-persistedstate来持久化，默认用的是localStorage的存储方式
安装

npm install vuex-persistedstate --save-dev

在store.js里引入

import createPersistedState from 'vuex-persistedstate'

const store = new Vuex.Store({
  state: {
    username: '',
    companyId: ''
  },
  mutations: {
     getUsername(state, payload) {
      // sessionStorage.setItem('username', JSON.stringify(payload))
      state.username = payload
    },
  getCompanyId(state, payload) {
      state.companyId = payload
    },
},
plugins: [
    createPersistedState(
      {
        reducer(state) {//state就是vuex的state对象
          return {
            companyId: state.companyId,
            username111: state.username,//username111:保存的key，s.username:保存的value
          }
        }
      }
    ),
  ],
})