表单控件绑定

基础用法

可以用 v-model 指令在表单控件元素上创建双向数据绑定。根据控件类型它自动选取正确的方法更新元素。尽管有点神奇，v-model 不过是语法糖，在用户输入事件中更新数据，以及特别处理一些极端例子。

Text

<span>Message is: {{ message }}</span>
<br>
<input type="text" v-model="message" placeholder="edit me">

{% raw %}
<div id="example-1" class="demo">
  <span>Message is: {{ message }}</span><br>
  <input type="text" v-model="message" placeholder="edit me">
</div>
<script>
new Vue({
  el: '#example-1',
  data: {
    message: ''
  }
})
</script>
{% endraw %}

Checkbox

单个勾选框，逻辑值：

<input type="checkbox" id="checkbox" v-model="checked">
<label for="checkbox">{{ checked }}</label>

{% raw %}
<div id="example-2" class="demo">
  <input type="checkbox" id="checkbox" v-model="checked">
  <label for="checkbox">{{ checked }}</label>
</div>
<script>
new Vue({
  el: '#example-2',
  data: {
    checked: false
  }
})
</script>
{% endraw %}

多个勾选框，绑定到同一个数组：

<input type="checkbox" id="jack" value="Jack" v-model="checkedNames">
<label for="jack">Jack</label>
<input type="checkbox" id="john" value="John" v-model="checkedNames">
<label for="john">John</label>
<input type="checkbox" id="mike" value="Mike" v-model="checkedNames">
<label for="mike">Mike</label>
<br>
<span>Checked names: {{ checkedNames | json }}</span>

new Vue({
  el: '...',
  data: {
    checkedNames: []
  }
})

{% raw %}
<div id="example-3" class="demo">
  <input type="checkbox" id="jack" value="Jack" v-model="checkedNames">
  <label for="jack">Jack</label>
  <input type="checkbox" id="john" value="John" v-model="checkedNames">
  <label for="john">John</label>
  <input type="checkbox" id="mike" value="Mike" v-model="checkedNames">
  <label for="mike">Mike</label>
  <br>
  <span>Checked names: {{ checkedNames | json }}</span>
</div>
<script>
new Vue({
  el: '#example-3',
  data: {
    checkedNames: []
  }
})
</script>
{% endraw %}

Radio

<input type="radio" id="one" value="One" v-model="picked">
<label for="one">One</label>
<br>
<input type="radio" id="two" value="Two" v-model="picked">
<label for="two">Two</label>
<br>
<span>Picked: {{ picked }}</span>

{% raw %}
<div id="example-4" class="demo">
  <input type="radio" id="one" value="One" v-model="picked">
  <label for="one">One</label>
  <br>
  <input type="radio" id="two" value="Two" v-model="picked">
  <label for="two">Two</label>
  <br>
  <span>Picked: {{ picked }}</span>
</div>
<script>
new Vue({
  el: '#example-4',
  data: {
    picked: ''
  }
})
</script>
{% endraw %}

Select

单选：

<select v-model="selected">
  <option selected>A</option>
  <option>B</option>
  <option>C</option>
</select>
<span>Selected: {{ selected }}</span>

{% raw %}
<div id="example-5" class="demo">
  <select v-model="selected">
    <option selected>A</option>
    <option>B</option>
    <option>C</option>
  </select>
  <span>Selected: {{ selected }}</span>
</div>
<script>
new Vue({
  el: '#example-5',
  data: {
    selected: null
  }
})
</script>
{% endraw %}

多选（绑定到一个数组）：

<select v-model="selected" multiple>
  <option selected>A</option>
  <option>B</option>
  <option>C</option>
</select>
<br>
<span>Selected: {{ selected | json }}</span>

{% raw %}
<div id="example-6" class="demo">
  <select v-model="selected" multiple style="width: 50px">
    <option selected>A</option>
    <option>B</option>
    <option>C</option>
  </select>
  <br>
  <span>Selected: {{ selected | json }}</span>
</div>
<script>
new Vue({
  el: '#example-6',
  data: {
    selected: []
  }
})
</script>
{% endraw %}

动态选项，用 v-for 渲染：

<select v-model="selected">
  <option v-for="option in options" v-bind:value="option.value">
    {{ option.text }}
  </option>
</select>
<span>Selected: {{ selected }}</span>

new Vue({
  el: '...',
  data: {
    selected: 'A',
    options: [
      { text: 'One', value: 'A' },
      { text: 'Two', value: 'B' },
      { text: 'Three', value: 'C' }
    ]
  }
})

{% raw %}
<div id="example-7" class="demo">
  <select v-model="selected">
    <option v-for="option in options" v-bind:value="option.value">
      {{ option.text }}
    </option>
  </select>
  <span>Selected: {{ selected }}</span>
</div>
<script>
new Vue({
  el: '#example-7',
  data: {
    selected: 'A',
    options: [
      { text: 'One', value: 'A' },
      { text: 'Two', value: 'B' },
      { text: 'Three', value: 'C' }
    ]
  }
})
</script>
{% endraw %}

值绑定

对于单选按钮，勾选框及选择框选项，v-model 绑定的值通常是静态字符串（对于勾选框是逻辑值）：

<!-- 当选中时，`picked` 为字符串 "a" -->
<input type="radio" v-model="picked" value="a">

<!-- `toggle` 为 true 或 false -->
<input type="checkbox" v-model="toggle">

<!-- 当选中时，`selected` 为字符串 "abc" -->
<select v-model="selected">
  <option value="abc">ABC</option>
</select>

但是有时我们想绑定值到 Vue 实例一个动态属性上。可以用 v-bind 做到。 而且 v-bind 允许绑定输入框的值到非字符串值。

Checkbox

<input
  type="checkbox"
  v-model="toggle"
  v-bind:true-value="a"
  v-bind:false-value="b">

// 选中
vm.toggle === vm.a
// 取消选中
vm.toggle === vm.b

Radio

<input type="radio" v-model="pick" v-bind:value="a">

// 选中
vm.pick === vm.a

Select Options