Vue常用的组件通信方式

组建通信的基本模式:父子组件的关系可以总结为 prop 向下传递，事件向上传递。父组件通过 prop 给子组件下发数据，子组件通过事件给父组件发送消息

组件通信的常用三种方式

1.props(父组件向子组件传值)

parent.vue

 <template>
  <p>
    <parent-child :childName="childName"></parent-child>
  </p>
</template>

<script>
  import child from "./child"
  export default {
    components: {
      "parent-child" : child
    },data(){
      return {
        childName : "我是child哦"
      }
    }
  }
</script>

child.vue

<template>
  <p id="child">
    child的名字叫:{{childName}}<br>
  </p>
</template>

<script>
  export default {
    props:{
      childName :{
        type:String,
        default: ""
      }
    }
  }
</script>

2.$emit(子组件向父组件传值–局部消息订阅)

parent.vue

<template>
  <p>
    <parent-child :childName="childName" @childNotify="childReceive"></parent-child>
  </p>
</template>

<script>
  import child from "./child"
  export default {
    components: {
      "parent-child" : child
    },data(){
      return {
        childName : "我是child哦"
      }
    },methods:{
      childReceive(params){
        this.$message(params)
      }
    }
  }
</script>

child.vue

<template>
  <p id="child">
    child的名字叫:{{childName}}<br>
  </p>
</template>

<script>
  export default {
    props:{
      childName :{
        type:String,
        default: ""
      }
    },methods:{
      childNotify(params){
        this.$emit("childNotify","child的名字叫"+this.childName);
      }
    }
  }
</script>

3.bus全局消息订阅

bus.js

const install = (Vue) => {
  const Bus = new Vue({
    methods: {
      on (event, ...args) {
        this.$on(event, ...args);
      },
      emit (event, callback) {
        this.$emit(event, callback);
      },
      off (event, callback) {
        this.$off(event, callback);
      }
    }
  })
  Vue.prototype.$bus = Bus;
}
export default install;

mAIn.js

import Bus from "./assets/js/bus";
Vue.use(Bus);

child.vue

<template>
  <p id="child">
    child的名字叫:{{childName}}<br>
    <el-button type="primary" @click="brotherNotity">向child2打招呼</el-button>
  </p>
</template>

<script>
  export default {
    props:{
      childName :{
        type:String,
        default: ""
      }
    },methods:{
      childNotify(params){
        this.$emit("childNotify","child的名字叫"+this.childName);
      },
      brotherNotity(){
        this.$bus.$emit("child2","child2你好呀");
      }
    }
  }
</script>

child2.vue

<template>
  <p id="child2">
    child2的名字叫:{{child2Name}}
  </p>
</template>

<script>
  export default {
    props:{
      child2Name :{
        type:String,
        default: ""
      }
    },
    created(){
      this.$bus.$on("child2",function(params){
        this.$message(params)
      })
    },
    beforeDestroy() {
      this.$bus.$off("child2",function(){
        this.$message("child2-bus销毁")
      })
    }
  }
</script>