vue3 コンポーネント通信のいくつかの方法についての簡単な説明

<script setup>
    // 方法一：useContext() vue3.2 之后已经舍弃
    import { useContext } from &#39;vue&#39;
    const ctx = useContext()
    // 对外暴露属性方法等都可以
    ctx.expose({
        childName: &#39;这是子组建的属性&#39;,
        someMethod(){
        console.log(&#39;这是子组件的方法&#39;)
        }
    })
</script>

// Parent.vue 注意 ref="comp"
<template>
    <child ref="comp"></child>
    <button @click="handleClick">按钮</button>
</template>
<script>
    import child from &#39;./child.vue&#39;
    import { ref } from &#39;vue&#39; 
    const comp = ref(null)
    const handleClick = () => {
        console.log(comp.value.childName)
        comp.value.someMethod() // 调用子组件对外暴露的方法
    }
</script>

// 父组件
<child :msg1="msg1" :msg2="msg2" title="3333"></child>
<script setup>
    import child from &#39;./child.vue&#39;
    import { ref,reactive } from &#39;vue
    const msg1 = ref(&#39;111&#39;)
    const msg2 = ref(&#39;222&#39;)
</script>

// 子组件
<script setup>
    import { defineProps,useContext,useAttars } from &#39;vue&#39;
    const props = defineProps({
        msg1: String
    })
    
    // 方法1
    const ctx = useContext()
    console.log(ctx.attars) // {msg2:&#39;222&#39;,title:&#39;333&#39;}
    
    // 方法2 
    const attrs = useAttars()
    console.log(attars)  // {msg2:&#39;2222&#39;,title:&#39;3333&#39;}
</script>

<child v-model:key="key" v-modle:value="value" />
<script>
    import child from &#39;./child.vue&#39;
    import { ref,reactive } from &#39;vue&#39;
    const key = ref(&#39;111&#39;)
    const value = ref(&#39;222&#39;)
</script>

//子组件
<template>
   <button @click="handleClick"></button>
</template>
<script setup>
    // 方法一  v3.2 已被移除
    import { useContext } from &#39;vue&#39;
    const { emit } = useContext()
    
    // 方法二
    import { defineEmits } from &#39;vue&#39;
    const emit = defineEmits([&#39;key&#39;,&#39;value&#39;])
    
    //用法
    const handleClick = () => {
        emit(&#39;update:key&#39;,&#39;新的key&#39;)
        emit(&#39;update:value&#39;,&#39;新的value&#39;)
    }
</script>

    // 父组件
    <script setup>
        import { provide } from &#39;vue&#39;
        const name = provide(&#39;name&#39;)
        console.log(&#39;name&#39;,&#39;沐华&#39;)
    </script>
    //子组件
    <script setup>
        import { inject } from &#39;vue&#39;
        const name = inject(&#39;name&#39;)
        console.log(name) //木华
    </script>

mitt.js
import mitt from 'mitt'
const mitt = mitt()
export default mitt

// 组件A 
<script setup>
    import mitt from &#39;./mitt&#39;
    const handleClick = () => {
        mitt.emit(&#39;handleChange&#39;)
    }
</script>
// 组件B 
<script setup>
import mitt from &#39;./mitt&#39;
import { onUnmounted } from &#39;vue&#39;
const someMethod = () => {...}
mitt.on(&#39;handleChange&#39;,someMethod)
onUnmounted(()=>{
    mitt.off(&#39;handleChange&#39;,someMethod)
})
</script>