props/$emit 适用父子组件通信

ref与parent/children适用父子组件通信

attrs/listeners,provide/inject 适用于隔代组件通信

vuex,EventBus(事件总线) 适用于父子、隔代、兄弟组件通信

slot插槽方式

attrs实例

父组件（这时候我们传了两个参数title和type）

<template>
  <div>
    <div class="father">我是父组件，点击传值给孙子组件</div>
    <child :title="title" :type="type" />
  </div>
</template>
<script>
import child from "./components/child";
export default {
  components: {
    child
  },
  data() {
    return {
      title: "",
      type: ""
    };
  },
  methods: {}
};
</script>

子组件（注意：子组件使用了title，那么孙子组件就拿不到title值。）

<template>
  <div>
    <div class="child">
      <div>我是子组件{{title}}</div>
    </div>
    <grandson v-bind="$attrs" />
  </div>
</template>
<script>
import grandson from "./grandson";

export default {
  components: {
    grandson
  },
  props: {
    title: {
      type: String,
      default: ""
    }
  },
  watch: {
    $attrs() {
      console.log(this.$attrs, "attrs");
    },
  },
  data() {}
};
</script>

孙子组件（该组件只能显示type）

<template>
  <div>
    <div class="grandson">我是孙子组件{{title}}{{type}}</div>
  </div>
</template>
<script>
export default {
  props: {
    title: {
      type: String,
      default: ""
    },
    type: {
      type: String,
      default: ""
    }
  },
  watch: {
    title() {
      console.log(this.title, "=====孙子组件");
    },
    type() {
      console.log(this.type, "=====孙子组件");
    }
  },
  data() {
    return {};
  }
};
</script>