<template>
    <div id="app" >
        <router-view></router-view>
    </div>
</template>

<script>
    import Setting from '@/setting';
    export default {
    name: 'App',
    created () {
        //在页面加载时读取sessionStorage里的状态信息
        if (sessionStorage.getItem(Setting.storeKey) ) {
            this.$store.replaceState(Object.assign({}, this.$store.state,JSON.parse(sessionStorage.getItem(Setting.storeKey))))
        } 

        //在页面刷新时将vuex里的信息保存到sessionStorage里
        window.addEventListener("beforeunload",()=>{    
            sessionStorage.getItem(Setting.usernameKey) && sessionStorage.setItem(Setting.storeKey,JSON.stringify(this.$store.state))
        })                                                                                      
    }
    }
</script>