Vue使用v-show编写登录/退出切换，程序如下：

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>v-show</title>
    <script src="js/vue.js"></script>
</head>
<body>
<div id="app">
    <h2 v-show="isLogin==false">
        <!--使用<a>link方式-->
        <a href="javascript:" @click="login">登录,</a><span>注册</span>
    </h2>
    <h2 v-show="isLogin == true">你已登录<a href="javascript:" @click="logout">,退出</a></h2>
</div>

<script>
    var vue = new Vue({
        el: "#app",
        data: {
            isLogin: false
        },
        methods: {
            login() {
                this.isLogin = true;
            },
            logout() {
                this.isLogin = false;
            }
        }
    });
</script>
</body>
</html>