組件沒有提出來，都寫在一個(gè)文件里的

// index.js

// Login組件里的第一個(gè) input 綁定了一個(gè) v-model='username'
const Login = { template: '<form class="form login"><h2>登陸</h2><input v-model="username" type="username" class="form-control" placeholder="username" required autofocus><input class="form-control" type="password" placeholder="Password" required><button type="submit">登陸</button></form>' }
const SignUp = { template: '<form class="form signup"><h2>注冊(cè)新用戶</h2><input type="username" id="inputUsername" class="form-control" placeholder="username" required autofocus><input type="password" id="inputPassword" class="form-control" placeholder="Password" required><input type="email" id="inputEmail" class="form-control" placeholder="Email address" required><button type="submit">注冊(cè)</button></form>' }

const routes = [
  { path: '/', component: Login },
  { path: '/login', component: Login },
  { path: '/signUp', component: SignUp }
]

const router = new VueRouter({
  routes 
})

// 在data里面也有 username
const app = new Vue({
  router,
  data: {
      username: ''
  }
}).$mount('#app')

為什么會(huì)報(bào)錯(cuò)：

去掉 v-model='username' 和 data 是能夠正常運(yùn)行的
如果我想獲取 input 里用戶輸入的值應(yīng)該怎么做呢