vuejs中使用v-model对表单数据的收集

表单收集的信息针对有text/textarea，checkbox，radio，select

举个例子：

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>08_表单输入绑定</title>
</head>
<body>
<div id="demo">
  <form action="/xxx" @submit.prevent="handleSubmit">
    <span>用户名: </span>
    <input type="text" v-model="username"><br>

    <span>密码: </span>
    <input type="password" v-model="pwd"><br>

    <span>性别: </span>
    <input type="radio" id="female" value="女" v-model="sex">
    <label for="female">女</label>
    <input type="radio" id="male" value="男" v-model="sex">
    <label for="male">男</label><br>

    <span>爱好: </span>
    <input type="checkbox" id="basket" value="basket" v-model="likes">
    <label for="basket">篮球</label>
    <input type="checkbox" id="foot" value="foot" v-model="likes">
    <label for="foot">足球</label>
    <input type="checkbox" id="pingpang" value="pingpang" v-model="likes">
    <label for="pingpang">乒乓</label><br>

    <span>城市: </span>
    <select v-model="cityId">
      <option value="">未选择</option>
      <option :value="city.id" v-for="(city, index) in allCitys" :key="city.id">{{city.name}}</option>
    </select><br>
    <span>介绍: </span>
    <textarea rows="10" v-model="info"></textarea><br><br>

    <input type="submit" value="注册">
  </form>
</div>

<script type="text/javascript" src="../js/vue.js"></script>
<script type="text/javascript">
  new Vue({
    el: '#demo',
    data: {
      username: '',
      pwd: '',
      sex: '男',
      likes: ['foot'],
      allCitys: [{id: 1, name: 'BJ'}, {id: 2, name: 'SS'}, {id: 3, name: 'SZ'}],
      cityId: '',
      info: ''
    },
    methods: {
      handleSubmit () {
        console.log(this.username, this.pwd, this.sex, this.likes, this.cityId, this.info)
        alert('提交注册的ajax请求')
      }
    }
  })
</script>
</body>
</html>

运行结果：

提示点：

1.参考官方文档： https://cn.vuejs.org/v2/guide/forms.html#%E5%9F%BA%E7%A1%80%E7%94%A8%E6%B3%95

2.城市选择时，当选中时，vm.cityId == vm.city.id，依据

3.:key 到底有什么用？按照文档中的意思是：

一个列表项要有一个key值,这个key值如果唯一且未发生变化,则dom就会被复用,反之则需要重新生成。