Vue.js 发射不会引发父方法执行

Question

I just started experimenting with Vue.js

I try to implement crud operations in a Todo app using Vue.js

My code fails to delete a todo item

The deletion of a todo item is implemented in the parent class

<template>
  <div>
    <p>Completed Tasks: {{todos.filter(todo => {return todo.done === true}).length}}</p>
    <p>Pending Tasks: {{todos.filter(todo => {return todo.done === false}).length}}</p>
    // we are now passing the data to the todo component to render the todo list
    <todo v-for="todo in todos" v-bind:todo="todo" v-bind:key="todo.id"></todo>
  </div>
</template>

<script type = "text/javascript" >
    import Todo from './Todo';

    export default {
      props: ['todos'],
      components: {
          Todo,
      },

      methods: {
        completeTodo(todo) {
            const todoIndex = this.todos.indexOf(todo);
            this.todos[todoIndex].done = true;
        },
        deleteTodo(todo) {
          const todoIndex = this.todos.indexOf(todo);
          this.todos.splice(todoIndex, 1);
        },
      },
    };
</script>

The delete action is an event on the child class , which should trigger the delete action in the parent

<template>
  <div class='ui centered card'>
    // Todo shown when we are not in editing mode.
    <div class="content" v-show="!isEditing">
      <div class='header'>
          {{ todo.title }}
      </div>
      <div class='meta'>
          {{ todo.project }}
      </div>
      <div class='extra content'>
        <span class='right floated edit icon' v-on:click="showForm">
            <i class='edit icon'></i>
        </span>
        /* add the trash icon in below the edit icon in the template */
        <span class='right floated trash icon' v-on:click="deleteTodo(todo)">
            <i class='trash icon'></i>
        </span>
      </div>
    </div>
    // form is visible when we are in editing mode
    <div class="content" v-show="isEditing">
      <div class='ui form'>
        <div class='field'>
          <label>Title</label>
          <input type='text' v-model="todo.title" />
        </div>
        <div class='field'>
          <label>Project</label>
          <input type='text' v-model="todo.project" />
        </div>
        <div class='ui two button attached buttons'>
          <button class='ui basic blue button' v-on:click="hideForm">
            Close X
          </button>
        </div>
      </div>
    </div>
    <div class='ui bottom attached green basic button' v-on:click="changeStatus(todo)" v-show="!isEditing && todo.done" disabled>
        Completed
    </div>
    <div class='ui bottom attached red basic button' v-on:click="completeTodo(todo)" v-show="!isEditing && !todo.done">
        Pending
    </div>
  </div>
</template>
<script>
export default {
  props: ['todo'],
  data() {
    return {
      isEditing: false,
    };
  },
  methods: {
    showForm() {
      this.isEditing = true;
    },
    hideForm() {
      this.isEditing = false;
    },
    completeTodo(todo) {
      this.$emit('complete-todo', todo);
    },
    changeStatus(todo){
      todo.done = !todo.done;
    },
    deleteTodo(todo) {
      this.$emit('delete-todo', todo);
    },
  },
};
</script>

Answer 1

You need to add v-on:complete-todo="completeTodo" and v-on:deleteTodo="deleteTodo" to your <todo> s.

( or @complete-todo="completeTodo" instead of v-on:

if you are using Vue3, your Todo.vue also needs a list of events that this component can propagate

emits: ['delete-todo', 'complete-todo'],

Answer 2

<todo v-for="todo in todos" v-bind:todo="todo" v-bind:key="todo.id" @delete-todo="deleteTodo" @ complete-todo="completeTodo"></todo>

try this