vue 3 发出警告“无关的非发射事件监听器”

Question

我正在尝试使用组合 API

将数据从子项发送到父项

我收到以下警告。

[Vue warn]: Extraneous non-emits event listeners (updatedcount) were passed to component but could not be automatically inherited because component renders fragment or text root nodes. If the listener is intended to be a component custom event listener only, declare it using the "emits" option.at <HelloWorld onUpdatedcount=fn > at

childcomponent.vue


<template>
  <h1>{{ store.count }}</h1>
  <button @click="fired">click me</button>
</template>

<script>
import useStore from "../store/store.js";
export default {
  name: "HelloWorld",
  setup(_,{ emit }) {
    const store = useStore();

    const fired = () => {
      store.count++;
      emit("updatedcount", store.count);
    };

    return {
      store,
      fired
    };
  },
};
</script>

parentcomponent.vue


<template>
  <div>
    {{ hello }}
    <br />
    <br />
    <input type="text" v-model="hello.searchQuery" />
    <br><br>
    <button @click="hello.count--">click me too!</button>
    <hello-world @updatedcount="mydata" />
  </div>
</template>

<script>
import HelloWorld from "./components/HelloWorld.vue";
import useStore from "./store/store.js";

export default {
  components: {
    HelloWorld,
  },
  setup() {
    const hello = useStore();

    function mydata(event) {
      console.log(event);
    }

    return {
      hello,
      mydata
    };
  },
};
</script>

Answer 1

我认为您需要在组件中定义 emits：https://v3.vuejs.org/guide/component-custom-events.html#defining-custom-events

export default {
  name: "HelloWorld",
  emits: ["updatedcount"], // <--- add this line
  setup(_,{ emit }) {
    ...
  },
};

Answer 2

更新：

在 vue 3 脚本设置中你会做

const emits = defineEmits(["updatedcount"])

emits("updatedcount", store.count);

vue 3 发出警告“无关的非发射事件监听器”

vue 3 emit warning " Extraneous non-emits event listeners"

javascript

eventemitter

vue.js

vuejs3

vue-composition-api