模板地址：vue官网上的示例
1 输入框输入，回车添加todo信息
2 每条todo信息后增加删除按钮
3 每条todo信息增加complete状态，列表前增加checkbox，选中后修改complete值，根据complete值修改todo信息样式
4 编辑：双击todo信息隐藏checkout、info、button，显示输入框，回车或失去焦点完成编辑，esc退出编辑
5 提示剩余未完成todo数量，清除已完成todo
6 增加显示筛选条件
7 全选
8 将数据保存在localStorage中
9 加样式
<html>
<head>
<script src="https://cdn.jsdelivr.net/npm/vue@2/dist/vue.js"></script>
<style>
.completed {
text-decoration: line-through;
color: lightgray;
}
#root {
border: 1px solid darkgray;
}
header {
border-bottom: 1px solid lightgray;
height: 30px;
padding: 5px;
}
input {
margin: 0;
padding: 0;
}
header>.allDone {
display: inline-block;
vertical-align: -webkit-baseline-middle;
width: 15px;
}
header>.newTodo {
outline: none;
border: none;
vertical-align: sub;
}
ul {
padding: 0;
margin: 0;
}
ul>li {
list-style-type: none;
padding: 5px;
border-bottom: 1px solid lightgray;
}
button {
border-color: transparent;
background-color: transparent;
color: darkgray;
float: right;
}
footer {
height: 24px;
padding: 0 5px;
color: darkgray;
font-size: 12px;
line-height: 24px;
text-align: center;
position: relative;
}
footer> :first-child {
float: left;
}
footer .filter {
position: absolute;
left: 50%;
transform: translate(-50%, 0);
}
footer .filter a {
margin: 0 2px;
}
footer .checked {
border: 1px solid lightgray;
}
</style>
</head>
<body>
<div id="root">
<header>
<!-- 全选 -->
<div class="allDone">
<input v-show="todoList.length" type="checkbox" v-model="allDone" />
</div>
<!-- 输入框 -->
<input class="newTodo" v-model="newTodo" @keyup.enter="addTodo" />
</header>
<!-- todo列表 -->
<ul>
<li v-for="(todo, index) in filterTodoList" :class="{completed: todo.completed}">
<div v-show="editTodoIndex != index">
<!-- 状态勾选 -->
<input type="checkbox" v-model="todo.completed" />
<!-- todo信息 -->
<label @dblClick="editTodo(todo, index)">{
{todo.info}}</label>
<!-- 删除按钮 -->
<button @click="removeTodo(index)">x</button>
</div>
<!-- 编辑框 -->
<input style="marginLeft: 20px" v-show="editTodoIndex == index" v-model="todo.info"
@blur="doneEdit(todo, index)" @keyup.enter="doneEdit(todo, index)"
@keyup.esc="cancelEdit(todo, index)" />
</li>
</ul>
<footer v-show="todoList.length">
<!-- 未完成todo数 -->
<a>剩下{
{remainCount}}</a>
<!-- 不同状态筛选 -->
<div class="filter">
<a :class="{checked: visible == 'all'}" @click="changeVisible('all')">所有</a>
<a :class="{checked: visible == 'active'}" @click="changeVisible('active')">未完成</a>
<a :class="{checked: visible == 'completed'}" @click="changeVisible('completed')">已完成</a>
</div>
<!-- 清除已完成todo -->
<button v-show="todoList.length > remainCount" @click="clearComplete">清除已完成</button>
</footer>
</div>
<script>
var key = 'todoList';
// 不同状态的筛选函数
var filters = {
all: function (todoList) {
return todoList;
},
active: function (todoList) {
return todoList.filter(todo => !todo.completed);
},
completed: function (todoList) {
return todoList.filter(todo => todo.completed)
}
}
// fetch从localstorage中获取数据，save将数据保存到localstorage中
var todoStorage = {
fetch: function () {
return JSON.parse(localStorage.getItem(key) || "[]");
},
save: function (todoList) {
localStorage.setItem(key, JSON.stringify(todoList));
}
}
var app = new Vue({
el: "#root",
data: {
newTodo: "", // 新增输入框的内容
todoList: todoStorage.fetch(), // 所有todo信息，数组元素：{completed: 完成true/未完成false，info：todo信息string}
editTodoIndex: -1, // 正在编辑的todo信息的index，没有todo信息正在编辑即为-1
beforeEditCache: "", // 暂存编辑之前的todo信息，退出编辑后需要赋值回去
visible: 'all' //当前筛选状态
},
methods: {
// 回车添加事件
addTodo: function () {
if (this.newTodo) {
this.todoList.push({
info: this.newTodo, completed: false })
}
this.newTodo = '';
},
// 删除事件
removeTodo: function (index) {
this.todoList.splice(index, 1)
},
// 开始编辑，保存编辑之前的todo信息，todo信息的index
editTodo: function (todo, index) {
this.beforeEditCache = todo.info; // 不要保存整个todo，因为编辑的时候直接改变todo.info,beforeEditCache也会改变
this.editTodoIndex = index;
},
// 完成编辑，将editTodoIndex恢复初始值，如果输入框为空，则删除当前todo
doneEdit: function (todo, index) {
this.editTodoIndex = -1;
if (!todo.info) {
this.removeTodo(index);
}
},
// 退出编辑
cancelEdit: function (todo, index) {
todo.info = this.beforeEditCache;
this.editTodoIndex = -1;
},
// 清除已完成
clearComplete: function () {
this.todoList = this.todoList.filter(todo => !todo.completed)
},
// 改变列表展示属性
changeVisible: function (visible) {
this.visible = visible
}
},
computed: {
// 实时计算剩余未完成todo数
remainCount: function () {
return this.todoList.filter(todo => !todo.completed).length;
},
// 根据筛选状态显示todo信息
filterTodoList: function () {
return filters[this.visible](this.todoList)
},
// 全选，get获取值，判断是否全部完成，set赋值，将所有事件的completed全部置true
allDone: {
get: function () {
return this.remainCount == 0;
},
set: function (value) {
this.todoList.forEach(todo => todo.completed = value);
}
}
},
watch: {
// 监听todoList，有改变的时候将新的数组保存到localstorage中
todoList: {
handler: function () {
todoStorage.save(this.todoList);
},
deep: true,
}
}
})
</script>
</body>
</html>