vuex頁面刷新后數據丟失的方法

// vuex mutations
const mutations = {
 setToken(state, token) {
 // 保存用戶認證Token
 sessionStorage.setItem('token', token);
 state.token = token;
 },
 setUser(state, user) {
 // 保存用戶信息
 sessionStorage.setItem('user', JSON.stringify(user));
 state.user = user;
 },
 // 注銷登錄，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;
 },
 // 獲取當前用戶登錄信息
 getUser(state) {
 if(state.user === null) {
 state.user = JSON.parse(sessionStorage.getItem('user'));
 }
 return state.user;
 }
};