• v-model 其实是一个语法糖 通过props 和 emit组合而成的
• 1. 默认值的改变
  • prop：value -> modelValue；
  • 事件：input -> update:modelValue；
  • v-bind 的 .sync 修饰符和组件的 model 选项已移除
  • 新增 支持多个v-model
  • 新增 支持自定义 修饰符

案例 子组件

<template>
    <div v-if='propData.modelValue ' class="dialog">
        <div class="dialog-header">
            <div>标题</div><div @click="close">x</div>
        </div>
        <div class="dialog-content">
           内容
        </div>
        
    </div>
</template>

<script setup lang='ts'>

type Props = {
  modelValue:boolean
}

const propData = defineProps<Props>()

const emit = defineEmits(['update:modelValue'])

const close = () => {
    emit('update:modelValue',false)
}

</script>

<style lang='less'>
.dialog{
   width: 300px;
   height: 300px;
   border: 1px solid #ccc;
   position: fixed;
   left:50%;
   top:50%;
   transform: translate(-50%,-50%);
   &-header{
       border-bottom: 1px solid #ccc;
       display: flex;
       justify-content: space-between;
       padding: 10px;
   }
   &-content{
       padding: 10px;
   }
}
</style>

父组件

<template>
  <button @click="show = !show">开关{{show}}</button>
  <Dialog v-model="show"></Dialog>
</template>
 
<script setup lang='ts'>
import Dialog from "./components/Dialog/index.vue";
import {ref} from 'vue'
const show = ref(false)
</script>
 
<style>
</style>

绑定多个案例

子组件

<template>
     <div v-if='modelValue ' class="dialog">
         <div class="dialog-header">
             <div>标题---{{title}}</div><div @click="close">x</div>
         </div>
         <div class="dialog-content">
            内容
         </div>
         
     </div>
</template>
 
<script setup lang='ts'>
 
type Props = {
   modelValue:boolean,
   title:string
}
 
const propData = defineProps<Props>()

// 重点
const emit = defineEmits(['update:modelValue','update:title'])
 
const close = () => {
     emit('update:modelValue',false)
     emit('update:title','我要改变')
}
 
</script>
 
<style lang='less'>
.dialog{
    width: 300px;
    height: 300px;
    border: 1px solid #ccc;
    position: fixed;
    left:50%;
    top:50%;
    transform: translate(-50%,-50%);
    &-header{
        border-bottom: 1px solid #ccc;
        display: flex;
        justify-content: space-between;
        padding: 10px;
    }
    &-content{
        padding: 10px;
    }
}
</style>

父组件

<template>
  <button @click="show = !show">开关{{show}} ----- {{title}}</button>
  <Dialog v-model:title='title' v-model.xxx="show"></Dialog>
</template>
 
<script setup lang='ts'>
import Dialog from "./components/Dialog/index.vue";
import {ref} from 'vue'
const show = ref(false)
const title = ref('我是标题')
</script>
 
<style>
</style>

自定义修饰符

• 添加到组件 v-model 的修饰符将通过 modelModifiers prop 提供给组件。在下面的示例中，我们创建了一个组件，其中包含默认为空对象的 modelModifiers prop

<script setup lang='ts'>
 
type Props = {
    modelValue: boolean,
    title?: string,
    modelModifiers?: {
        xxx: boolean // 是否添加了xxx修饰符
    }
    // v-model:title
    titleModifiers?: {
        default: () => {}
    }
 
}
 
const propData = defineProps<Props>()
 
const emit = defineEmits(['update:modelValue', 'update:title'])
 
const close = () => {
    console.log(propData.modelModifiers);
    if (propData.modelModifiers?.xxx) {
      // do something..
    }
 
    emit('update:modelValue', false)
    emit('update:title', '我要改变')
}