Vue-44、Vue中TodoList案例_自定义事件实现

1、App.vue

<template>
  <div id="app">
    <div class="todo-container">
      <div class="todo-wrap">
            <my-header @addTodo="addTodo"></my-header>
            <my-list :todos="todos" :changeDone="changeDone" :deleteToto="deleteToto"></my-list>
            <my-footer :todos="todos" @changeTodoDones="changeTodoDones" @clearTodoDone="clearTodoDone"></my-footer>
      </div>
    </div>
  </div>
</template>
<script>
import  MyHeader from './components/MyHeader'
import  MyFooter from './components/MyFooter'
import  MyList from './components/MyList'

export default {
  name: 'App',
  components: {
    MyHeader,MyList,MyFooter
  },
    data(){
      return{
          todos:JSON.parse(localStorage.getItem('todos')) || []
      }
    },

    watch:{
      todos:{
          deep:true,
          handler(newvalue) {
              localStorage.setItem('todos',JSON.stringify(newvalue));
          }
      }
    },
    methods:{
      addTodo(obj){
          // console.log(obj);
          this.todos.unshift(obj);
      },
        changeDone(id){
          this.todos.forEach((p)=>{
              if(p.id === id){
                  p.done = !p.done
              }
          })
        },
        deleteToto(id){
          this.todos=
          this.todos.filter(p=>p.id !== id);
        },
        changeTodoDones(value){
          console.log(value);
          this.todos.forEach(p=>{
              p.done=value;
          });
        },
        clearTodoDone(){
         this.todos=this.todos.filter(p=>{
              return !p.done
          })
        }
    },
}
</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-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>

2、MyFooter.vue

<template>
    <div class="todo-footer"  v-show="total" >
        <label>
            <input type="checkbox"  v-model="isAll" >
        </label>
        <span>
            <span>已完成{{totalDone}}</span> / 全部{{todos.length}}
        </span>
        <button class="btn btn-danger"  @click="removeTodoDone">清除已完成任务</button>
    </div>
</template>
<script >
    export default {
        name: "MyFooter",
        props:['todos'],
        computed:{
            total(){
                const  a = this.todos.length;
                return a>0 ? true : false;
            },
            totalDone(){
                const number = this.todos.reduce((pre,todo)=> pre + (todo.done ? 1 : 0),0);
                return number;
            },
            isAll:{
                get(){
                    return this.totalDone === this.todos.length && this.todos.length > 0;
                },
                set(value){
                    //this.changeTodoDones(value);
                    this.$emit('changeTodoDones',value)
                }
            },
        },
        methods:{
            removeTodoDone(){
                this.$emit('clearTodoDone');
                //this.clearTodoDone();
            }
        }
    }
</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>

3、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{
                title:''
            }
        },
        methods:{
            add(){
                if(!this.title.trim())  alert("输入不能为零") ;
                const obj = {id:nanoid(),title: this.title,done:false};
                //this.addTodo(obj);
                this.$emit('addTodo',obj);
                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>