vue3组件通信的方式总结及实例用法

<child :msg2="msg2" /><script setup>    const props = defineProps({        // 写法一        msg2:String        // 写法二        msg2:{            type:String,            default:''        }    })    console.log(props) // {msg2:'这是传级子组件的信息2'}</script>

//Child.vue<template>    // 写法一    <div @click="emit('myclick')">按钮</div>    // 写法二    <div @click="handleClick">按钮</div></template><script setup>    // 方法一    const emit = defineEmits(['myClick'],['myClick2'])    // 方法二    const handleClick = () => {        emit('myClick','这是发送给父组件的信息');     }           // 方法二 不适用于vue3.2，使用的useContext()已经舍弃     import { useContext } from 'vue'     const { emit } = useContext()     const handleClick = () => {       emit('myClick','这是发送给父组件的信息'        }</script> // Parent.vue响应<template>    <child @myClick="onMyClick"></child></template><script setup>    import child from "./child.vue"    import onMychilk = (msg) => {        console.log(msg) // 父组件收到的信息     }</script>

<script setup>    // 方法一：useContext() vue3.2 之后已经舍弃    import { useContext } from 'vue'    const ctx = useContext()    // 对外暴露属性方法等都可以    ctx.expose({        childName: '这是子组建的属性',        someMethod(){        console.log('这是子组件的方法')        }    })</script> // Parent.vue 注意 ref="comp"<template>    <child ref="comp"></child>    <button @click="handleClick">按钮</button></template><script>    import child from './child.vue'    import { ref } from 'vue'     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 './child.vue'    import { ref,reactive } from 'vue    const msg1 = ref('111')    const msg2 = ref('222')</script> // 子组件<script setup>    import { defineProps,useContext,useAttars } from 'vue'    const props = defineProps({        msg1: String    })         // 方法1    const ctx = useContext()    console.log(ctx.attars) // {msg2:'222',title:'333'}         // 方法2     const attrs = useAttars()    console.log(attars)  // {msg2:'2222',title:'3333'}</script>

<child v-model:key="key" v-modle:value="value" /><script>    import child from './child.vue'    import { ref,reactive } from 'vue'    const key = ref('111')    const value = ref('222')</script> //子组件<template>   <button @click="handleClick"></button></template><script setup>    // 方法一  v3.2 已被移除    import { useContext } from 'vue'    const { emit } = useContext()         // 方法二    import { defineEmits } from 'vue'    const emit = defineEmits(['key','value'])         //用法    const handleClick = () => {        emit('update:key','新的key')        emit('update:value','新的value')    }</script>

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

//store/index.jsimport { createStore } from 'vuex'export default createStore({    state:{count:1},    getters:{        getCount:state=>state.count    },    mutations:{        add(state){            state.count++        }    }   }) // main.js import { createApp } from 'vue' import APP from './App.vue' import store from './store' createApp(APP).use(store).mount("#app")   // 直接使用 <template>     <div>         {{ $store.state.count }}     </div>     <button @click="$store.commit('add')">     </button> </template>   // 获取 <script setup>     import { useStore,computed } from 'vuex'     const store = useStore()     console.log(store.state.count)           const count = computed (()=>store.state.count)     console.log(count) </script>

mitt.jsimport mitt from 'mitt'const mitt = mitt()export default mitt

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