1. Todo-List案例
1.src/components/MyHeader.vue（Header组件）
<template>
<div class="todo-header">
<input type="text" placeholder="请输入你的任务名称，按回车键确认" @keydown.enter="add" v-model="title"/>
</div>
</template>
<script>
import {nanoid} from 'nanoid'
export default {
name:'MyHeader',
data() {
return {
title:''
}
},
methods:{
add(){
if(!this.title.trim()) return
const todoObj = {id:nanoid(),title:this.title,done:false}
this.addTodo(todoObj)
this.title = ''
}
},
props:['addTodo']
}
</script>
<style scoped>
.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>
2.src/components/MyItem.vue（item组件，每一条）
<template>
<li>
<label>
<input type="checkbox" :checked="todo.done" @click="handleCheck(todo.id)"/>
<span>{{todo.title}}</span>
</label>
<button class="btn btn-danger" @click="handleDelete(todo.id,todo.title)">删除</button>
</li>
</template>
<script>
export default {
name:'MyItem',
props:['todo','checkTodo','deleteTodo'],
methods:{
handleCheck(id){
this.checkTodo(id)
},
handleDelete(id,title){
if(confirm("确定删除任务："+title+"吗？")){
this.deleteTodo(id)
}
}
}
}
</script>
<style scoped>
li {
list-style: none;
height: 36px;
line-height: 36px;
padding: 0 5px;
border-bottom: 1px solid #ddd;
}
li label {
float: left;
cursor: pointer;
}
li label li input {
vertical-align: middle;
margin-right: 6px;
position: relative;
top: -1px;
}
li button {
float: right;
display: none;
margin-top: 3px;
}
li:before {
content: initial;
}
li:last-child {
border-bottom: none;
}
li:hover {
background-color: #eee;
}
li:hover button{
display: block;
}
</style>
3.src/components/MyList.vue（list组件，容纳item组件）
<template>
<ul class="todo-main">
<MyItem
v-for="todo in todos"
:key="todo.id"
:todo="todo"
:checkTodo="checkTodo"
:deleteTodo="deleteTodo"
/>
</ul>
</template>
<script>
import MyItem from './MyItem.vue'
export default {
name:'MyList',
components:{MyItem},
props:['todos','checkTodo','deleteTodo']
}
</script>
<style scoped>
.todo-main {
margin-left: 0px;
border: 1px solid #ddd;
border-radius: 2px;
padding: 0px;
}
.todo-empty {
height: 40px;
line-height: 40px;
border: 1px solid #ddd;
border-radius: 2px;
padding-left: 5px;
margin-top: 10px;
}
</style>
4.src/components/MyFooter.vue（最底下的组件）
<template>
<div class="todo-footer" v-show="total">
<label>
<input type="checkbox" v-model="isAll"/>
</label>
<span>
<span>已完成{{doneTotal}}</span> / 全部{{total}}
</span>
<button class="btn btn-danger" @click="clearAll">清除已完成任务</button>
</div>
</template>
<script>
export default {
name:'MyFooter',
props:['todos','checkAllTodo','clearAllTodo'],
computed:{
doneTotal(){
return this.todos.reduce((pre,todo)=> pre + (todo.done ? 1 : 0) ,0)
},
total(){
return this.todos.length
},
isAll:{
get(){
return this.total === this.doneTotal && this.total > 0
},
set(value){
this.checkAllTodo(value)
}
}
},
methods:{
clearAll(){
this.clearAllTodo()
}
}
}
</script>
<style scoped>
.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>
5.src/App.vue（组件老大）
<template>
<div id="root">
<div class="todo-container">
<div class="todo-wrap">
<MyHeader :addTodo="addTodo"/>
<MyList :todos="todos" :checkTodo="checkTodo" :deleteTodo="deleteTodo"/>
<MyFooter :todos="todos" :checkAllTodo="checkAllTodo" :clearAllTodo="clearAllTodo"/>
</div>
</div>
</div>
</template>
<script>
import MyHeader from './components/MyHeader.vue'
import MyList from './components/MyList.vue'
import MyFooter from './components/MyFooter.vue'
export default {
name:'App',
components: { MyHeader,MyList,MyFooter },
data() {
return {
todos:[
{id:'001',title:'抽烟',done:false},
{id:'002',title:'喝酒',done:false},
{id:'003',title:'烫头',done:false},
]
}
},
methods:{
addTodo(todoObj){
this.todos.unshift(todoObj)
},
checkTodo(id){
this.todos.forEach((todo)=>{
if(todo.id === id) todo.done = !todo.done
})
},
deleteTodo(id){
this.todos = this.todos.filter(todo => todo.id !== id)
},
checkAllTodo(done){
this.todos.forEach(todo => todo.done = done)
},
clearAllTodo(){
this.todos = this.todos.filter(todo => !todo.done)
}
}
}
</script>
<style>
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>
总结：
组件化编码流程：
1.拆分静态组件：组件要按照功能点拆分，命名不要与html元素冲突
2.实现动态组件：考虑好数据的存放位置，数据是一个组件在用，还是一些组件在用：
1.一个组件在用：放在组件自身即可
2.一些组件在用：放在他们共同的父组件上（状态提升）
3.实现交互：从绑定事件开始
props适用于：
1.父组件传子组件 通信
2.子组件传父组件 通信（要求父组件先给子组件一个函数）
使用v-model时要切记：v-model绑定的值不能是props传过来的值，因为props是不可以修改的
props传过来的若是对象类型的值，修改对象中的属性时Vue不会报错，但不推荐这样做
2 WebStorage
1.localStorage
<!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">
<title>localStorage</title>
</head>
<body>
<h2>localStorage</h2>
<button onclick="saveDate()">点我保存数据</button><br/>
<button onclick="readDate()">点我读数据</button><br/>
<button onclick="deleteDate()">点我删除数据</button><br/>
<button onclick="deleteAllDate()">点我清空数据</button><br/>
<script>
let person = {name:"张三",age:20}
function saveDate(){
localStorage.setItem('msg','localStorage')
localStorage.setItem('person',JSON.stringify(person))
}
function readDate(){
console.log(localStorage.getItem('msg'))
const person = localStorage.getItem('person')
console.log(JSON.parse(person))
}
function deleteDate(){
localStorage.removeItem('msg')
localStorage.removeItem('person')
}
function deleteAllDate(){
localStorage.clear()
}
</script>
</body>
</html>
2.sessionStorage
<!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">
<title>sessionStorage</title>
</head>
<body>
<h2>sessionStorage</h2>
<button onclick="saveDate()">点我保存数据</button><br/>
<button onclick="readDate()">点我读数据</button><br/>
<button onclick="deleteDate()">点我删除数据</button><br/>
<button onclick="deleteAllDate()">点我清空数据</button><br/>
<script>
let person = {name:"张三",age:20}
function saveDate(){
sessionStorage.setItem('msg','sessionStorage')
sessionStorage.setItem('person',JSON.stringify(person))
}
function readDate(){
console.log(sessionStorage.getItem('msg'))
const person = sessionStorage.getItem('person')
console.log(JSON.parse(person))
}
function deleteDate(){
sessionStorage.removeItem('msg')
sessionStorage.removeItem('person')
}
function deleteAllDate(){
sessionStorage.clear()
}
</script>
</body>
</html>
总结：
1.存储内容大小一般支持5MB左右（不同浏览器可能还不一样）
2.浏览器端通过Window.sessionStorage和Window.localStorage属性来实现本地存储机制
3.相关API：
1.xxxStorage.setItem('key', 'value')：该方法接受一个键和值作为参数，会把键值对添加到存储中，如果键名存在，则更新其对应的值
2.xxxStorage.getItem('key')：该方法接受一个键名作为参数，返回键名对应的值
3.xxxStorage.removeItem('key')：该方法接受一个键名作为参数，并把该键名从存储中删除
4.xxxStorage.clear()：该方法会清空存储中的所有数据
备注：
1.SessionStorage存储的内容会随着浏览器窗口关闭而消失
2.LocalStorage存储的内容，需要手动清除才会消失
3.xxxStorage.getItem(xxx)如果 xxx 对应的 value 获取不到，那么getItem()的返回值是null
4.JSON.parse(null)的结果依然是null
3.使用本地存储优化Todo-List
src/App.vue
<template>
<div id="root">
<div class="todo-container">
<div class="todo-wrap">
<MyHeader :addTodo="addTodo"/>
<MyList :todos="todos" :checkTodo="checkTodo" :deleteTodo="deleteTodo"/>
<MyFooter :todos="todos" :checkAllTodo="checkAllTodo" :clearAllTodo="clearAllTodo"/>
</div>
</div>
</div>
</template>
<script>
import MyHeader from './components/MyHeader.vue'
import MyList from './components/MyList.vue'
import MyFooter from './components/MyFooter.vue'
export default {
name:'App',
components: { MyHeader,MyList,MyFooter },
data() {
return {
todos:JSON.parse(localStorage.getItem('todos')) || []
}
},
methods:{
addTodo(todoObj){
this.todos.unshift(todoObj)
},
checkTodo(id){
this.todos.forEach((todo)=>{
if(todo.id === id) todo.done = !todo.done
})
},
deleteTodo(id){
this.todos = this.todos.filter(todo => todo.id !== id)
},
checkAllTodo(done){
this.todos.forEach(todo => todo.done = done)
},
clearAllTodo(){
this.todos = this.todos.filter(todo => !todo.done)
}
},
watch:{
todos:{
deep:true,
handler(value){
localStorage.setItem('todos',JSON.stringify(value))
}
}
}
}
</script>
<style>
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>
|