<html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <title>Document</title> </head> <body> <!-- key解决input被复用的问题 --> <div id="app"> <span v-if="isUser"> <label for="username">用户账号</label> <input type="text" id="username" placeholder="请输入用户账号" key="username"> </span> <span v-else> <label for="email">用户邮箱</label> <input type="text" id="email" placeholder="请输入邮箱" key="email"> </span> <button @click="isUser = !isUser">切换类型</button> </div> <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script> <script> const app = new Vue({ el:'#app', data:{ isUser:true } }) </script> </body> </html>