To do

项目初始化

1. 在一个新建的文件夹下运行cmdvue create todo
2. 关闭eslint自动检查

3. yarn run serve

前期准备 创建工程和组件

1. 在compoments目录下创建3个vue文件作为组件复用

components/TodoHeader.vue - 复制标签和类名

<template>
  <ul class="todo-list">
    <!-- completed: 完成的类名 -->
    <li class="completed" >
      <div class="view">
        <input class="toggle" type="checkbox" />
        <label>任务名</label>
        <button class="destroy"></button>
      </div>
    </li>
  </ul>
  
</template>

<script>
export default {
}
</script>

components/TodoFooter.vue - 复制标签和类名

<template>
  <footer class="footer">
    <span class="todo-count">总计：<strong>数量值</strong></span>
    <ul class="filters">
      <li>
        <a class="selected" href="javascript:;" >全部</a>
      </li>
      <li>
        <a href="javascript:;">未完成</a>
      </li>
      <li>
        <a href="javascript:;" >已完成</a>
      </li>
    </ul>
    <button class="clear-completed" >清除已完成</button>
  </footer>
</template>

<script>
export default {

}
</script>

App.vue中引入和使用

<template>
  <section class="todoapp">
    <!-- 除了驼峰, 还可以使用-转换链接 -->
    <todo-header></todo-header>
    <todo-main></todo-main>
    <todo-footer></todo-footer>
  </section>
</template>

<script>
import TodoHeader from "./components/TodoHeader";
import TodoMain from "./components/TodoMain";
import TodoFooter from "./components/TodoFooter";

import "./styles/base.css"
import "./styles/index.css"
export default {
  components: {
    TodoHeader,
    TodoMain,
    TodoFooter,
  },
};
</script>

Tips 页面组件根元素添加类名todoapp

循环展示

App.vue

<todo-main :list="list"></todo-main>

export default {
  data() {
    return {
      list: [
        { id: 100, name: "吃饭", isDone: true },
        { id: 201, name: "睡觉", isDone: false },
        { id: 103, name: "打豆豆", isDone: true },
      ],
    };
  }
};

TodoMain.vue

<template>
  <ul class="todo-list">
    <!-- completed: 完成的类名 -->
    <li :class="{ completed: item.isDone }" v-for="item in list" :key="item.id">
      <div class="view">
        <input class="toggle" type="checkbox" v-model="item.isDone" />
        <label>{{ item.name }}</label>
        <button class="destroy"></button>
      </div>
    </li>
  </ul>
</template>

<script>
export default {
  props: ["list"]
};
</script>

<style>
</style>

添加功能

TodoHeader.vue

<template>
  <header class="header">
    <h1>todos</h1>
    <input id="toggle-all" class="toggle-all" type="checkbox" >
    <label for="toggle-all"></label>
    <input
      class="new-todo"
      placeholder="输入任务名称-回车确认"
      v-model="name"
      @keydown.enter="down"
    />
  </header>
</template>

<script>
export default {
    data(){
        return {
            name: ""
        }
    },
    methods: {
        down(ev){
            this.$emit("add", this.name)
            this.name = ""
        }
    }
}
</script>

App.vue

<todo-header @add="addFn"></todo-header>

methods: {
    // ...省略了原来的方法
    addFn(name){
        this.list.push({
            id: Date.now(),
            name,
            isDone: false
        })
    }
}

删除功能

App.vue - 传入自定义事件等待接收要被删除的id或索引

<todo-main :list="list" @del="delFn"></todo-main>

methods: {
    delFn(id) {
        // 把id过滤掉
        this.list = this.list.filter((item) => item.id !== id);
    },
},

TodoMain.vue - 把id传回去实现删除(想好数据在哪里, 就在哪里删除)

<button class="destroy" @click="del(item.id)"></button>

methods: {
    del(id) {
        // console.log(id)
        this.$emit("del", id);
    },
},

注意⚠️：通过子传父删除，以免影响后续不同状态下数据的删除操作