@[toc]

改动的地方

注意点：让每一个添加和删除的操作有一个柔和的动画效果，有两种方式。方式1：在MyItem添加动画效果使用\标签；方式2：在MyList中添加效果使用\标签。下面案例代码使用方式2。

MyList.vue

<transition-group name="todo" appear>
            <MyItem 
                v-for="todoObj in todos"
                :key="todoObj.id" 
                :todo="todoObj" 
            />
</transition-group>

<style scoped>
.todo-enter-active{
   
        animation: atguigu 0.5s linear;
    }

    .todo-leave-active{
   
        animation: atguigu 0.5s linear reverse;
    }

    @keyframes atguigu {
   
        from{
   
            transform: translateX(100%);
        }
        to{
   
            transform: translateX(0px);
        }
    }
</style>

案例全部代码

main.js

main.js

//引入Vue
import Vue from 'vue'
//引入App
import App from './App.vue'
//关闭Vue的生产提示
Vue.config.productionTip = false

//创建vm
new Vue({
   
    el:'#app',
    render: h => h(App),
    beforeCreate() {
   
        Vue.prototype.$bus = this
    },
})

App.vue

App.vue

<template>
    <div id="root">
        <div class="todo-container">
            <div class="todo-wrap">
                <MyHeader @addTodo="addTodo"/>
                <MyList :todos="todos"/>
                <MyFooter :todos="todos" @checkAllTodo="checkAllTodo" @clearAllTodo="clearAllTodo"/>
            </div>
        </div>
    </div>
</template>

<script>
    import pubsub from 'pubsub-js'
    import MyHeader from './components/MyHeader'
    import MyList from './components/MyList'
    import MyFooter from './components/MyFooter'

    export default {
   
        name:'App',
        components:{
   MyHeader,MyList,MyFooter},
        data() {
   
            return {
   
                //由于todos是MyHeader组件和MyFooter组件都在使用，所以放在App中（状态提升）
                todos:JSON.parse(localStorage.getItem('todos')) || []
            }
        },
        methods: {
   
            //添加一个todo
            addTodo(todoObj){
   
                this.todos.unshift(todoObj)
            },
            //勾选or取消勾选一个todo
            checkTodo(id){
   
                this.todos.forEach((todo)=>{
   
                    if(todo.id === id) todo.done = !todo.done
                })
            },
            //更新一个todo
            updateTodo(id,title){
   
                this.todos.forEach((todo)=>{
   
                    if(todo.id === id) todo.title = title
                })
            },
            //删除一个todo
            deleteTodo(_,id){
   
                this.todos = this.todos.filter( todo => todo.id !== id )
            },
            //全选or取消全选
            checkAllTodo(done){
   
                this.todos.forEach((todo)=>{
   
                    todo.done = done
                })
            },
            //清除所有已经完成的todo
            clearAllTodo(){
   
                this.todos = this.todos.filter((todo)=>{
   
                    return !todo.done
                })
            }
        },
        watch: {
   
            todos:{
   
                deep:true,
                handler(value){
   
                    localStorage.setItem('todos',JSON.stringify(value))
                }
            }
        },
        mounted() {
   
            this.$bus.$on('checkTodo',this.checkTodo)
            this.$bus.$on('updateTodo',this.updateTodo)
            this.pubId = pubsub.subscribe('deleteTodo',this.deleteTodo)
        },
        beforeDestroy() {
   
            this.$bus.$off('checkTodo')
            this.$bus.$off('updateTodo')
            pubsub.unsubscribe(this.pubId)
        },
    }
</script>

<style>
    /*base*/
    body {
   
        background: #fff;
    }
    .btn {
   
        display: inline-block;
        padding: 4px 12px;
        margin-bottom: 0;
        font-size: 14px;
        line-height: 20px;
        text-align: center;
        vertical-align: middle;
        cursor: pointer;
        box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.2), 0 1px 2px rgba(0, 0, 0, 0.05);
        border-radius: 4px;
    }
    .btn-danger {
   
        color: #fff;
        background-color: #da4f49;
        border: 1px solid #bd362f;
    }
    .btn-edit {
   
        color: #fff;
        background-color: skyblue;
        border: 1px solid rgb(103, 159, 180);
        margin-right: 5px;
    }
    .btn-danger:hover {
   
        color: #fff;
        background-color: #bd362f;
    }
    .btn:focus {
   
        outline: none;
    }
    .todo-container {
   
        width: 600px;
        margin: 0 auto;
    }
    .todo-container .todo-wrap {
   
        padding: 10px;
        border: 1px solid #ddd;
        border-radius: 5px;
    }
</style>

MyHeader.vue

MyHeader.vue

<template>
    <div class="todo-header">
        <input type="text" placeholder="请输入你的任务名称，按回车键确认" v-model="title" @keyup.enter="add"/>
    </div>
</template>

<script>
    import {
   nanoid} from 'nanoid'
    export default {
   
        name:'MyHeader',
        data() {
   
            return {
   
                //收集用户输入的title
                title:''
            }
        },
        methods: {
   
            add(){
   
                //校验数据
                if(!this.title.trim()) return alert('输入不能为空')
                //将用户的输入包装成一个todo对象
                const todoObj = {
   id:nanoid(),title:this.title,done:false}
                //通知App组件去添加一个todo对象
                this.$emit('addTodo',todoObj,1,2,3)
                //清空输入
                this.title = ''
            }
        },
    }
</script>

<style scoped>
    /*header*/
    .todo-header input {
   
        width: 560px;
        height: 28px;
        font-size: 14px;
        border: 1px solid #ccc;
        border-radius: 4px;
        padding: 4px 7px;
    }

    .todo-header input:focus {
   
        outline: none;
        border-color: rgba(82, 168, 236, 0.8);
        box-shadow: inset 0 1px 1px rgba(0, 0, 0, 0.075), 0 0 8px rgba(82, 168, 236, 0.6);
    }
</style>

MyList.vue

MyList.vue

<template>
    <ul class="todo-main">
        <transition-group name="todo" appear>
            <MyItem 
                v-for="todoObj in todos"
                :key="todoObj.id" 
                :todo="todoObj" 
            />
        </transition-group>
    </ul>
</template>

<script>
    import MyItem from './MyItem'

    export default {
   
        name:'MyList',
        components:{
   MyItem},
        //声明接收App传递过来的数据
        props:['todos']
    }
</script>

<style scoped>
    /*main*/
    .todo-main {
   
        margin-left: 0px;
        border: 1px solid #ddd;
        border-radius: 2px;
        padding: 0px;
    }

    .todo-empty {
   
        height: 40px;
        line-height: 40px;
        border: 1px solid #ddd;
        border-radius: 2px;
        padding-left: 5px;
        margin-top: 10px;
    }

    .todo-enter-active{
   
        animation: atguigu 0.5s linear;
    }

    .todo-leave-active{
   
        animation: atguigu 0.5s linear reverse;
    }

    @keyframes atguigu {
   
        from{
   
            transform: translateX(100%);
        }
        to{
   
            transform: translateX(0px);
        }
    }
</style>

MyItem.vue

MyItem.vue

<template>
    <li>
        <label>
            <input type="checkbox" :checked="todo.done" @change="handleCheck(todo.id)"/>
            <!-- 如下代码也能实现功能，但是不太推荐，因为有点违反原则，因为修改了props -->
            <!-- <input type="checkbox" v-model="todo.done"/> -->
            <span v-show="!todo.isEdit">{
   {
   todo.title}}</span>
            <input 
                type="text" 
                v-show="todo.isEdit" 
                :value="todo.title" 
                @blur="handleBlur(todo,$event)"
                ref="inputTitle"
            >
        </label>
        <button class="btn btn-danger" @click="handleDelete(todo.id)">删除</button>
        <button v-show="!todo.isEdit" class="btn btn-edit" @click="handleEdit(todo)">编辑</button>
    </li>
</template>

<script>
    import pubsub from 'pubsub-js'
    export default {
   
        name:'MyItem',
        //声明接收todo
        props:['todo'],
        methods: {
   
            //勾选or取消勾选
            handleCheck(id){
   
                //通知App组件将对应的todo对象的done值取反
                // this.checkTodo(id)
                this.$bus.$emit('checkTodo',id)
            },
            //删除
            handleDelete(id){
   
                if(confirm('确定删除吗？')){
   
                    //通知App组件将对应的todo对象删除
                    // this.deleteTodo(id)
                    // this.$bus.$emit('deleteTodo',id)
                    pubsub.publish('deleteTodo',id)
                }
            },
            //编辑
            handleEdit(todo){
   
                if(todo.hasOwnProperty('isEdit')){
   
                    todo.isEdit = true
                }else{
   
                    // console.log('@')
                    this.$set(todo,'isEdit',true)
                }
                this.$nextTick(function(){
   
                    this.$refs.inputTitle.focus()
                })
            },
            //失去焦点回调（真正执行修改逻辑）
            handleBlur(todo,e){
   
                todo.isEdit = false
                if(!e.target.value.trim()) return alert('输入不能为空！')
                this.$bus.$emit('updateTodo',todo.id,e.target.value)
            }
        },
    }
</script>

<style scoped>
    /*item*/
    li {
   
        list-style: none;
        height: 36px;
        line-height: 36px;
        padding: 0 5px;
        border-bottom: 1px solid #ddd;
    }

    li label {
   
        float: left;
        cursor: pointer;
    }

    li label li input {
   
        vertical-align: middle;
        margin-right: 6px;
        position: relative;
        top: -1px;
    }

    li button {
   
        float: right;
        display: none;
        margin-top: 3px;
    }

    li:before {
   
        content: initial;
    }

    li:last-child {
   
        border-bottom: none;
    }

    li:hover{
   
        background-color: #ddd;
    }

    li:hover button{
   
        display: block;
    }
</style>

MyFooter.vue

MyFooter.vue

<template>
    <div class="todo-footer" v-show="total">
        <label>
            <!-- <input type="checkbox" :checked="isAll" @change="checkAll"/> -->
            <input type="checkbox" v-model="isAll"/>
        </label>
        <span>
            <span>已完成{
   {
   doneTotal}}</span> / 全部{
   {
   total}}
        </span>
        <button class="btn btn-danger" @click="clearAll">清除已完成任务</button>
    </div>
</template>

<script>
    export default {
   
        name:'MyFooter',
        props:['todos'],
        computed: {
   
            //总数
            total(){
   
                return this.todos.length
            },
            //已完成数
            doneTotal(){
   
                //此处使用reduce方法做条件统计
                /* const x = this.todos.reduce((pre,current)=>{
                    console.log('@',pre,current)
                    return pre + (current.done ? 1 : 0)
                },0) */
                //简写
                return this.todos.reduce((pre,todo)=> pre + (todo.done ? 1 : 0) ,0)
            },
            //控制全选框
            isAll:{
   
                //全选框是否勾选
                get(){
   
                    return this.doneTotal === this.total && this.total > 0
                },
                //isAll被修改时set被调用
                set(value){
   
                    // this.checkAllTodo(value)
                    this.$emit('checkAllTodo',value)
                }
            }
        },
        methods: {
   
            /* checkAll(e){
                this.checkAllTodo(e.target.checked)
            } */
            //清空所有已完成
            clearAll(){
   
                // this.clearAllTodo()
                this.$emit('clearAllTodo')
            }
        },
    }
</script>

<style scoped>
    /*footer*/
    .todo-footer {
   
        height: 40px;
        line-height: 40px;
        padding-left: 6px;
        margin-top: 5px;
    }

    .todo-footer label {
   
        display: inline-block;
        margin-right: 20px;
        cursor: pointer;
    }

    .todo-footer label input {
   
        position: relative;
        top: -1px;
        vertical-align: middle;
        margin-right: 5px;
    }

    .todo-footer button {
   
        float: right;
        margin-top: 5px;
    }
</style>