Vue2.4+新增属性.sync、$attrs、$listeners的具体使用

//父组件
<template>
 <div class="parent">
  <p>父组件传入子组件的值：{{name}}</p>
  <fieldset>
   <legend>子组件</legend>
   <child :val="name" @update="modify">
   </child>
  </fieldset>
 </div>
</template>

<script>
import Child from './Child'
export default {
 components:{Child},
 data () {
  return {
   name:'linda'
  }
 },
 methods:{
  modify(newVal){
   this.name=newVal
  }
 }
}
</script>

//子组件
<template>
  <label class="child">
    输入框：
    <input :value=val @input="$emit('update',$event.target.value)"/>
  </label>
</template>
<script>
export default {
  props:['val']
}
</script>

//父组件
<template>
 <div class="parent">
  <p>父组件传入子组件的值：{{name}}</p>
  <fieldset>
   <legend>子组件</legend>
   <child :val.sync="name">
   </child>
  </fieldset>
 </div>
</template>

<script>
import Child from './Child'
export default {
 components:{Child},
 data () {
  return {
   name:'linda'
  }
 }
}
</script>

//子组件
<template>
  <label class="child">
    输入框：
    <input :value=val @input="$emit('update:val',$event.target.value)"/>
  </label>
</template>
<script>
export default {
  props:['val']
}
</script>

props:['type','placeholder','title',...]

//父组件
<my-input placeholder="请输入你的姓名" type="text" title="姓名" v-model="name"/>

<template>
  <div>
    <label>输入框：</label><input v-bind="$attrsAll" @input="$emit('input',$event.target.value)"/>
  </div>
</template>
<script>
export default {
  inheritAttrs:false,
  computed: {
    $attrsAll() {
      return {
        value: this.$vnode.data.model.value,
        ...this.$attrs
      }
    }
  }
}
</script>

<template>
  <div>
    <label>输入框：</label><input v-bind="$attrs" :value="value" @input="$emit('input',$event.target.value)"/>
  </div>
</template>
<script>
export default {
  inheritAttrs:false,
  props:['value']
}
</script>

<my-input @focus="focus" placeholder="请输入你的姓名" type="text" title="姓名" v-model="name"/>

<template>
  <div>
    <label>输入框：</label><input v-bind="$attrsAll" v-on="$listenserAll"/>
  </div>
</template>
<script>
export default {
  inheritAttrs:false,
  props:['value'],
  computed:{
     $attrsAll() {
      return {
        value: this.value,
        ...this.$attrs
      }
    },
    $listenserAll(){
      return Object.assign(
        {},
        this.$listeners,
        {input:(event) => this.$emit('input',event.target.value)})
    }
  }
}
</script>