Vue 阶段练习：记事本

将 Vue快速入门和 Vue 指令的学习成果应用到实际场景中（如该练习记事本），我们能够解决实际问题并提升对 Vue 的技能掌握。

功能展示

需求分析

我的代码

案例代码

知识点总结

功能展示

需求分析

列表渲染
删除功能
添加功能
底部统计和清空

我的代码

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>017练习：记事本v1</title>
    <script src="https://cdn.jsdelivr.net/npm/vue@2/dist/vue.js"></script>
    <style>
        div.app{
            height: 125px;
            width: 200px;
            padding: 25px 25px 25px 25px;
        }
        div.boxYard{
            background-color: gainsboro;
        }
        div.boxInside{
            background-color: white;
        }
        div.boxBlank{
            border: 1px solid orangered;
        }
        span.addButton{
            color: orangered;
        }
        
    </style>
</head>

<body>
    <div id="app">
        <div class="boxYard">
            <h1>记事本</h1>
            <div class="boxInside">
                <div class="boxBlank">
                    <input type="text" v-model="thing" placeholder="请输入任务">
                    <span class="addButton">
                        <button @click="add()">添加任务</button>
                    </span>
                </div>
                <ol>
                    <li v-for="(item,index) in toDoList" :key="item.id">
                        
                        <span>{{item.des}}</span>
                        <span class="delButton"><button @click="del(item.id)">×</button></span>
                    </li>
                </ol>
            </div>
        </div>
    </div>

    <script>
        const vm = new Vue({
            el: '#app',
            data: {
                thing:'',
                toDoList:[
                    {id:1, des:'跑步锻炼20分钟'},
                    {id:2,des:'复习数组语法'},
                ]
            },
            methods: {
                del(id){
                    this.toDoList=this.toDoList.filter(item=>item.id!=id)
                },
                add(){
                    this.toDoList.push({
                        id:this.id++,
                        des:this.thing
                    })
                    this.thing=''
                },
                clear() {
                    this.toDoList=[]
                }
            }

        })
    </script>
</body>

</html>

案例代码

html,
body {
  margin: 0;
  padding: 0;
}

body {
  background: #fff;
}

button {
  margin: 0;
  padding: 0;
  border: 0;
  background: none;
  font-size: 100%;
  vertical-align: baseline;
  font-family: inherit;
  font-weight: inherit;
  color: inherit;
  -webkit-appearance: none;
  appearance: none;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font: 14px 'Helvetica Neue', Helvetica, Arial, sans-serif;
  line-height: 1.4em;
  background: #f5f5f5;
  color: #4d4d4d;
  min-width: 230px;
  max-width: 550px;
  margin: 0 auto;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  font-weight: 300;
}

:focus {
  outline: 0;
}

.hidden {
  display: none;
}

#app {
  background: #fff;
  margin: 180px 0 40px 0;
  padding: 15px;
  position: relative;
  box-shadow: 0 2px 4px 0 rgba(0, 0, 0, 0.2), 0 25px 50px 0 rgba(0, 0, 0, 0.1);
}

#app .header input {
  border: 2px solid rgba(175, 47, 47, 0.8);
  border-radius: 10px;
}

#app .add {
  position: absolute;
  right: 15px;
  top: 15px;
  height: 68px;
  width: 140px;
  text-align: center;
  background-color: rgba(175, 47, 47, 0.8);
  color: #fff;
  cursor: pointer;
  font-size: 18px;
  border-radius: 0 10px 10px 0;
}

#app input::-webkit-input-placeholder {
  font-style: italic;
  font-weight: 300;
  color: #e6e6e6;
}

#app input::-moz-placeholder {
  font-style: italic;
  font-weight: 300;
  color: #e6e6e6;
}

#app input::input-placeholder {
  font-style: italic;
  font-weight: 300;
  color: gray;
}

#app h1 {
  position: absolute;
  top: -120px;
  width: 100%;
  left: 50%;
  transform: translateX(-50%);
  font-size: 60px;
  font-weight: 100;
  text-align: center;
  color: rgba(175, 47, 47, 0.8);
  -webkit-text-rendering: optimizeLegibility;
  -moz-text-rendering: optimizeLegibility;
  text-rendering: optimizeLegibility;
}

.new-todo,
.edit {
  position: relative;
  margin: 0;
  width: 100%;
  font-size: 24px;
  font-family: inherit;
  font-weight: inherit;
  line-height: 1.4em;
  border: 0;
  color: inherit;
  padding: 6px;
  box-shadow: inset 0 -1px 5px 0 rgba(0, 0, 0, 0.2);
  box-sizing: border-box;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.new-todo {
  padding: 16px;
  border: none;
  background: rgba(0, 0, 0, 0.003);
  box-shadow: inset 0 -2px 1px rgba(0, 0, 0, 0.03);
}

.main {
  position: relative;
  z-index: 2;
}

.todo-list {
  margin: 0;
  padding: 0;
  list-style: none;
  overflow: hidden;
}

.todo-list li {
  position: relative;
  font-size: 24px;
  height: 60px;
  box-sizing: border-box;
  border-bottom: 1px solid #e6e6e6;
}

.todo-list li:last-child {
  border-bottom: none;
}

.todo-list .view .index {
  position: absolute;
  color: gray;
  left: 10px;
  top: 20px;
  font-size: 22px;
}

.todo-list li .toggle {
  text-align: center;
  width: 40px;
  /* auto, since non-WebKit browsers doesn't support input styling */
  height: auto;
  position: absolute;
  top: 0;
  bottom: 0;
  margin: auto 0;
  border: none;
  /* Mobile Safari */
  -webkit-appearance: none;
  appearance: none;
}

.todo-list li .toggle {
  opacity: 0;
}

.todo-list li .toggle+label {
  /*
		Firefox requires `#` to be escaped - https://bugzilla.mozilla.org/show_bug.cgi?id=922433
		IE and Edge requires *everything* to be escaped to render, so we do that instead of just the `#` - https://developer.microsoft.com/en-us/microsoft-edge/platform/issues/7157459/
	*/
  background-image: url('data:image/svg+xml;utf8,%3Csvg%20xmlns%3D%22http%3A//www.w3.org/2000/svg%22%20width%3D%2240%22%20height%3D%2240%22%20viewBox%3D%22-10%20-18%20100%20135%22%3E%3Ccircle%20cx%3D%2250%22%20cy%3D%2250%22%20r%3D%2250%22%20fill%3D%22none%22%20stroke%3D%22%23ededed%22%20stroke-width%3D%223%22/%3E%3C/svg%3E');
  background-repeat: no-repeat;
  background-position: center left;
}

.todo-list li .toggle:checked+label {
  background-image: url('data:image/svg+xml;utf8,%3Csvg%20xmlns%3D%22http%3A//www.w3.org/2000/svg%22%20width%3D%2240%22%20height%3D%2240%22%20viewBox%3D%22-10%20-18%20100%20135%22%3E%3Ccircle%20cx%3D%2250%22%20cy%3D%2250%22%20r%3D%2250%22%20fill%3D%22none%22%20stroke%3D%22%23bddad5%22%20stroke-width%3D%223%22/%3E%3Cpath%20fill%3D%22%235dc2af%22%20d%3D%22M72%2025L42%2071%2027%2056l-4%204%2020%2020%2034-52z%22/%3E%3C/svg%3E');
}

.todo-list li label {
  word-break: break-all;
  padding: 15px 15px 15px 60px;
  display: block;
  line-height: 1.2;
  transition: color 0.4s;
}

.todo-list li.completed label {
  color: #d9d9d9;
  text-decoration: line-through;
}

.todo-list li .destroy {
  display: none;
  position: absolute;
  top: 0;
  right: 10px;
  bottom: 0;
  width: 40px;
  height: 40px;
  margin: auto 0;
  font-size: 30px;
  color: #cc9a9a;
  margin-bottom: 11px;
  transition: color 0.2s ease-out;
}

.todo-list li .destroy:hover {
  color: #af5b5e;
}

.todo-list li .destroy:after {
  content: '×';
}

.todo-list li:hover .destroy {
  display: block;
}

.todo-list li .edit {
  display: none;
}

.todo-list li.editing:last-child {
  margin-bottom: -1px;
}

.footer {
  color: #777;
  padding: 10px 15px;
  height: 20px;
  text-align: center;
  border-top: 1px solid #e6e6e6;
}

.footer:before {
  content: '';
  position: absolute;
  right: 0;
  bottom: 0;
  left: 0;
  height: 50px;
  overflow: hidden;
  box-shadow: 0 1px 1px rgba(0, 0, 0, 0.2), 0 8px 0 -3px #f6f6f6,
    0 9px 1px -3px rgba(0, 0, 0, 0.2), 0 16px 0 -6px #f6f6f6,
    0 17px 2px -6px rgba(0, 0, 0, 0.2);
}

.todo-count {
  float: left;
  text-align: left;
}

.todo-count strong {
  font-weight: 300;
}

.filters {
  margin: 0;
  padding: 0;
  list-style: none;
  position: absolute;
  right: 0;
  left: 0;
}

.filters li {
  display: inline;
}

.filters li a {
  color: inherit;
  margin: 3px;
  padding: 3px 7px;
  text-decoration: none;
  border: 1px solid transparent;
  border-radius: 3px;
}

.filters li a:hover {
  border-color: rgba(175, 47, 47, 0.1);
}

.filters li a.selected {
  border-color: rgba(175, 47, 47, 0.2);
}

.clear-completed,
html .clear-completed:active {
  float: right;
  position: relative;
  line-height: 20px;
  text-decoration: none;
  cursor: pointer;
}

.clear-completed:hover {
  text-decoration: underline;
}

.info {
  margin: 50px auto 0;
  color: #bfbfbf;
  font-size: 15px;
  text-shadow: 0 1px 0 rgba(255, 255, 255, 0.5);
  text-align: center;
}

.info p {
  line-height: 1;
}

.info a {
  color: inherit;
  text-decoration: none;
  font-weight: 400;
}

.info a:hover {
  text-decoration: underline;
}

/*
	Hack to remove background from Mobile Safari.
	Can't use it globally since it destroys checkboxes in Firefox
*/
@media screen and (-webkit-min-device-pixel-ratio: 0) {

  .toggle-all,
  .todo-list li .toggle {
    background: none;
  }

  .todo-list li .toggle {
    height: 40px;
  }
}

@media (max-width: 430px) {
  .footer {
    height: 50px;
  }

  .filters {
    bottom: 10px;
  }
}

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8" />
  <meta http-equiv="X-UA-Compatible" content="IE=edge" />
  <meta name="viewport" content="width=device-width, initial-scale=1.0" />
  <link rel="stylesheet" href="D:\\Vue\\0414\\017index.css" />
  <title>017练习：记事本v2</title>
</head>

<body>

  <!-- 主体区域 -->
  <section id="app">
    <!-- 输入框 -->
    <header class="header">
      <h1>记事本</h1>
      <input v-model="todoName" placeholder="请输入任务" class="new-todo" />
      <button @click="add" class="add">添加任务</button>
    </header>
    <!-- 列表区域 -->
    <section class="main">
      <ul class="todo-list">
        <li class="todo" v-for="(item, index) in list" :key="item.id">
          <div class="view">
            <span class="index">{{ index + 1 }}.</span> <label>{{ item.name }}</label>
            <button @click="del(item.id)" class="destroy"></button>
          </div>
        </li>
      </ul>
    </section>
    <!-- 统计和清空 → 如果没有任务了，底部隐藏掉 → v-show -->
    <footer class="footer" v-show="list.length > 0">
      <!-- 统计 -->
      <span class="todo-count">合 计:<strong> {{ list.length }} </strong></span>
      <!-- 清空 -->
      <button @click="clear" class="clear-completed">
        清空任务
      </button>
    </footer>
  </section>

  <!-- 底部 -->
  <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
  <script>
    // 添加功能
    // 1. 通过 v-model 绑定 输入框 → 实时获取表单元素的内容
    // 2. 点击按钮，进行新增，往数组最前面加 unshift
    const app = new Vue({
      el: '#app',
      data: {
        todoName: '',
        list: [
          { id: 1, name: '跑步一公里' },
          { id: 2, name: '跳绳200个' },
          { id: 3, name: '游泳100米' },
        ]
      },
      methods: {
        del(id) {
          // console.log(id) => filter 保留所有不等于该 id 的项
          this.list = this.list.filter(item => item.id !== id)
        },
        add() {
          if (this.todoName.trim() === '') {
            alert('请输入任务名称')
            return
          }
          this.list.unshift({
            id: +new Date(),
            name: this.todoName
          })
          this.todoName = ''
        },
        clear() {
          this.list = []
        }
      }
    })

  </script>
</body>

</html>