效果如下：
用到了如下的技术：
1.列表渲染：v-for key的设置
2.删除功能：v-on调用参数 fliter过滤 覆盖修改原数组
3.添加功能：v-model绑定，unshift修改原数组添加
html文件如下：
<!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="index.css" /><!-- 这里需要改为自己的文件路径！！！ -->
<title>记事本案例</title>
</head>
<body>
<!-- 主体区域 -->
<section id="app">
<!-- 输入框 -->
<header class="header">
<h1>BM记事本</h1>
<input v-model="todoName" placeholder="请输入任务" class="new-todo" /><!-- v-model双向绑定 -->
<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>
<!-- 底部 -->
<footer class="footer" v-show="List.length > 0"><!-- 数组为空，隐藏底部 -->
<!-- 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>
<script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
<script>
const app = new Vue({
el: '#app',
data: {
todoName: '',
List: [
{id: 1, name: "玩耍1小时"},
{id: 2, name: "今年要带着团队做出来几个项目"},
{id: 3, name: "今年的课程要好好上"}
]
},
methods: {
del (id) {
this.List = this.List.filter(item => item.id !== id)//保留下数组中id与参数id不相等的元素==删除参数id元素。
},
add () {
if(this.todoName.trim() === '') {//添加的数据为空，则不会添加。
alert("任务名称不能为空")
return
}
this.List.unshift({//不为空，接收id和name
id: +new Date(),
name: this.todoName
})
//清空
this.todoName = ''//添加完后输入栏清空
},
clear () {
this.List = []
}
}
})
</script>
</body>
</html>
css文件如下：
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;
}
}
