Vuejs 3 从子组件向父组件发出事件

Question

我最近开始使用 VueJS，我正在使用 v3，并且似乎在调用父级方法时遇到了问题。 child 中的 emit 函数似乎没有发出事件，并且 parent 中没有任何内容。

我已经包含了父母和孩子，以展示我是如何设置它的

家长

<template>
  <First/>
  < Child v-bind:sample="sample" @enlarge-text="onEnlargeText"/>
</template>

<script lang="ts">
import { defineComponent } from 'vue';
import axios from 'axios';
import First from './First.vue';
import Child from './Child.vue';

export default defineComponent({
  name: 'Container',
  components: {
    First,
    Child,
  },
  methods: {
    onEnlargeText() {
      console.log('enlargeText');
    },
  },
  data: () => ({
    sample: [],
    parentmessage: '',
  }),
  created() {
    axios.get('http://localhost:8080/getData')
      .then((response) => {
        console.log(response);
        this.sample = response.data;
      })
      .catch((error) => {
        console.log(error);
      });
  },
});
</script>

儿童

<template>
  <div id="add">
    <form id="signup-form" @submit.prevent="submit">
      <label for="text">Text:</label>
      <input type="text" v-model="text" required>
      <p class="error" >{{ error }}</p>
      <div class="field has-text-right">
        <button type="submit" class="button is-danger">Submit</button>
      </div>
    </form>
    <button v-on:click="tryThis">
      Enlarge text
    </button>
</div>
</template>

<script lang="ts">
import { defineComponent, ref } from 'vue';
import axios from 'axios';

interface SampleInterface {
  text: string;
  error: string;
}

export default defineComponent({
  name: 'Add',
  data: (): AddInterface => ({
    text: '',
    error: '',
  }),
  methods: {
    tryThis() {
      this.$emit('enlarge-text');
    },
    submit() {
      this.$emit('enlarge-text');
    },
  },
});
</script>

这应该怎么做？有什么我错过的吗？

我想知道我还能在这里使用$emit 吗？

Answer 1

您应该添加包含发出事件名称的新 emits option：

孩子：

<template>
  <div id="child">
    <button v-on:click="tryThis">Enlarge text</button>
  </div>
</template>

<script lang="ts">
import { defineComponent } from "vue";

export default defineComponent({
  name: "Child",
  emits: ["enlargeText"],
  methods: {
    tryThis() {
      console.log("trying");
      this.$emit("enlargeText", "someValue");
    },
  },
});
</script>

家长：

<template>
  <div>
    <p>Container</p>
    <Child @enlargeText="onEnlargeText" />
  </div>
</template>

<script lang="ts">
import { defineComponent } from "vue";
import Child from "./Child.vue";

export default defineComponent({
  name: "UrlContainer",
  components: {
    Child,
  },
  methods: {
    onEnlargeText() {
      console.log("enlarging text");
    },
  },
});
</script>

LIVE DEMO