v-如果不显示bloc不显示

Question

在用户身份验证中， 我试图更改主页显示，并显示“欢迎用户”和“注销”

我的问题是v-if的值不会随router.push更改。我必须刷新页面才能显示此块

<template>
    <div>
        <form class="login" @submit.prevent="login">
            <h1>Sign in</h1>
            <label>Email</label>
            <input required v-model="email" type="email" placeholder="Name"/>
            <label>Password</label>
            <input required v-model="password" type="password" placeholder="Password"/>
            <hr/>
            <button type="submit">Login</button>
        </form>
    </div>
</template>

<script>
    export default {
        data(){
            return {
                email : "",
                password : ""
            }
        },
        methods: {
            login: function () {
                let email = this.email 
                let password = this.password
                this.$store.dispatch('login', { email, password })
                    .then(() => this.$router.push('/'))
                    .catch(err => console.log(err))
            }
        }
    }
</script>

和app.vue： 模板：

 <span v-if="isLoggedIn"> {{user.email}} </span>
 <span v-if="isLoggedIn"> | <a @click="logout">Logout</a></span>

在脚本中

computed : {
    isLoggedIn : function(){ return this.$store.getters.isLoggedIn}
}