Vue3兄弟组件传值之mitt怎么安装使用

比起 Vue 实例上的 EventBus，mitt.js 好在哪里呢？

• 首先它足够小，仅有200bytes。

• 其次支持全部事件的监听和批量移除。

• 它还不依赖 Vue 实例，可以跨框架使用，React 或者 Vue，甚至 jQuery 项目都能使用同一套库。

项目中安装mitt

npm install --save mitt

使用方式一：在原型中声明

一、在 main.ts\color{#ef2d26}{main.ts}main.ts 中注册挂载到全局

import { createApp } from 'vue'
import App from './App.vue'
import mitt from 'mitt'
import router from "./router";

const app = createApp(App)

// vue3挂载到全局
app.config.globalProperties.$mitt = mitt();

app.use(router).mount('#app')

二、在home.vue组件中使用 emit\color{#ef2d26}{emit}emit 发送信息

<template>
    <div class="home-container">
        <p>这里是home组件</p>
        <button @click="sendMitt">$mitt发送数据</button>
        <About></About>
    </div>
</template>

<script lang="ts" setup>
import { getCurrentInstance, ref, ComponentInternalInstance } from &#39;vue&#39;;
import About from &#39;../about/about.vue&#39;

const { appContext } = getCurrentInstance() as ComponentInternalInstance;
const money = ref<number>(98);

const sendMitt = () => {
    appContext.config.globalProperties.$mitt.emit(&#39;moneyEvent&#39;, money.value += 2);
}

</script>

<style lang="less">
</style>

二、在about.vue组件中使用 on\color{#ef2d26}{on}on 接收信息

<template>
    <div class="about-container">
        <p>这里是about组件</p>
        <p>接收到的数据：{{ amount }}</p>
    </div>
</template>

<script lang="ts" setup>
import { ref, getCurrentInstance, ComponentInternalInstance, onBeforeMount, onMounted } from &#39;vue&#39;;

const amount = ref(0);
const { appContext } = getCurrentInstance() as ComponentInternalInstance;

onMounted(() => {
    appContext.config.globalProperties.$mitt.on(&#39;moneyEvent&#39;, (res: number) => {
        amount.value = res;
    })
})

onBeforeMount(() => {
    appContext.config.globalProperties.$mitt.off(&#39;moneyEvent&#39;);
});

</script>

<style lang="less">
.about-container {
    background-color: #f0f0f0;
}
</style>

使用方式二：在组件中引用

一、新建 bus.ts\color{#ef2d26}{bus.ts}bus.ts 文件

import mitt from "mitt";
const emiter = mitt();
export default emiter;

二、在home.vue组件中引入并使用 emit\color{#ef2d26}{emit}emit 发送信息

<template>
    <div class="home-container">
        <p>这里是home组件</p>
        <button @click="sendMitt">$mitt发送数据</button>
        <About></About>
    </div>
</template>

<script lang="ts" setup>
import { ref } from &#39;vue&#39;;
import About from &#39;../about/about.vue&#39;
import emitter from &#39;../../utils/bus&#39;

const money = ref<number>(98);

const sendMitt = () => {
    emitter.emit(&#39;moneyEvent&#39;, money.value += 2);
}
</script>

<style lang="less">
</style>

二、在about.vue组件中引入并使用 on\color{#ef2d26}{on}on 接收信息

<template>
    <div class="about-container">
        <p>这里是about组件</p>
        <p>接收到的数据：{{ amount }}</p>
    </div>
</template>

<script lang="ts" setup>
import { ref, onBeforeMount, onMounted } from &#39;vue&#39;;
import emitter from &#39;../../utils/bus&#39;

const amount = ref(0);

onMounted(() => {
    emitter.on(&#39;moneyEvent&#39;, (res: any) => {
        amount.value = res;
    });
})

onBeforeMount(() => {
    emitter.off(&#39;moneyEvent&#39;);
});

</script>

<style lang="less">
.about-container {
    background-color: #f0f0f0;
}
</style>