vuex页面刷新后数据丢失的方法

// vuex mutations
const mutations = {
  setToken(state, token) {
    // 保存用户认证Token
    sessionStorage.setItem('token', token);
    state.token = token;
  },
  setUser(state, user) {
    // 保存用户信息
    sessionStorage.setItem('user', JSON.stringify(user));
    state.user = user;
  },
  // 注销登录，清除token
  logout(state) {
    state.token = null;
    state.user = null;
    sessionStorage.removeItem('token');
    sessionStorage.removeItem('user');
  }
};

// vuex getters
const getters = {
  getToken(state){
    if(state.token === null){
      state.token = sessionStorage.getItem('token')
    }
    return state.token;
  },
  // 获取当前用户登录信息
  getUser(state) {
    if(state.user === null) {
      state.user = JSON.parse(sessionStorage.getItem('user'));
    }
    return state.user;
  }
};