Vue
Vue.js是前端三大新框架:Angular.js、React.js、Vue.js之一,Vue.js目前的使用和关注程度在三大框架中稍微胜出,并且它的热度还在递增。
Vue.js读音 /vjuː/, 类似于 view
Vue.js是一个轻巧、高性能、可组件化的MVVM库,同时拥有非常容易上手的API
Vue.js是一个构建数据驱动的Web界面的库
Vue.js是一套构建用户界面的 渐进式框架
通俗的说:
Vue作者
尤雨溪是Vue.js框架的作者,他认为,未来App的趋势是轻量化和细化,能解决问题的应用就是好应用。而在移动互联网时代大的背景下,个人开发者的机遇在门槛低,成本低,跨设备和多平台四个方面。
第一个Vue
官方提供了两个包
data
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<!-- 开发环境版本,包含了有帮助的命令行警告 -->
<script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
</head>
<body>
<div id="app">
<a href="#">{{ message }}</a>
<span>{{ hello }}</span>
<hr>
<span>{{ word }}</span>
</div>
</body>
<script type="text/javascript">
var vm = new Vue({
el:"#app",
data:{
message:"领取优惠卷",
hello:"hi en heng",
word:'你好!'
}
})
</script>
</html>
v-bind
<span v-bind:title="show">鼠标放在这里</span>
简写:
<span :title="show">鼠标放在这里</span>
var vm = new Vue({
el:"#app",
data:{
show:'当前时间是:'+ new Date().toLocaleString()
}
})
v-if
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<!-- 导入vue-->
<script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
</head>
<body>
<!--定义一个标签给id -->
<div id="app">
<span>{{ message }}</span>
<hr>
<a href="#" v-if="isLogin">欢迎你回来!</a>
<hr>
<a href="#" v-if="level === 1 ">青铜</a>
<a href="#" v-else-if="level === 2 ">白银</a>
<a href="#" v-else>王者</a>
<hr>
<span v-if="seen">v-if</span><br>
<span v-show="seen">v-show</span>
</div>
</body>
<!--创建vue实例-->
<script type="text/javascript">
var vm = new Vue({
el:'#app',
data:{
message:'hello',
is_Login:false,
level:2,
seen:false
}
})
</script>
</html>
v-show用法和v-if大致一样,但是它不支持v-else,它和v-if的区别是,它制作元素样式的显示和隐藏,元素一直是存在的
v-for
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<!-- 导入vue-->
<script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
</head>
<body>
<!--定义一个标签给id -->
<div id="app">
<span>{{ message }}</span>
<hr>
<ul>
<li v-for=" (item,index) in items">{{ index+1 }}----{{ item }}</li>
</ul>
<hr>
<!--对对象遍历-->
<ul>
<li v-for="(value,key) in object ">{{ key }}----{{ value }}</li>
</ul>
<hr>
<ul>
<li v-for="todo in todos">{{ todo.title}}---{{ todo.author}}</li>
</ul>
</div>
</body>
<!--创建vue实例-->
<script type="text/javascript">
var vm = new Vue({
el:'#app',
data:{
message:'hello',
items:['python','mysql','linux','html','js','css'],
object: {
title: 'How to do lists in Vue',
author: 'Jane Doe',
publishedAt: '2016-04-10'
},
todos: [
{
title: 'Vue',
author: 'Jane Doe',
publishedAt: '2016-04-10'
},
{
title: 'python',
author: 'Ricky',
publishedAt: '2019-04-10'
},
{
title: 'itcast',
author: 'itcast',
publishedAt: '2006-05-08'
}
]
}
})
</script>
</html>
methods
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<!-- 导入vue-->
<script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
</head>
<body>
<!--定义一个标签给id -->
<div id="app">
<span>{{ message }}</span>
<button v-on:click="login">登陆</button>
<br>
<a href="javascript:;" @click="regsiter">注册</a>
<hr>
<button @click="add(counter)">点击+1</button>
</div>
</body>
<!--创建vue实例-->
<script type="text/javascript">
var vm = new Vue({
//接管标签
el:'#app',
//绑定数据
data: {
message: 'hello',
counter:1,
total:0,
},
//方法
methods:{
login:function (){
alert('我被点击了')
},
regsiter:function (){
alert('注册')
},
add:function(counter){
//this表示当前的vue,我们通过this.total来获取data中的变量
this.total+= counter
alert(this.total)
}
}
})
</script>
</html>
v-on 绑定事件
简写@
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<!-- 导入vue-->
<script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
</head>
<body>
<!--定义一个标签给id -->
<div id="app">
<span>{{ message }}</span>
<button v-on:click="login">登陆</button>
<br>
<a href="javascript:;" @click="regsiter">注册</a>
<hr>
<button @click="add(counter)">点击+1</button>
</div>
</body>
<!--创建vue实例-->
<script type="text/javascript">
var vm = new Vue({
//接管标签
el:'#app',
//绑定数据
data: {
message: 'hello',
counter:1,
total:0,
},
//方法
methods:{
login:function (){
alert('我被点击了')
},
regsiter:function (){
alert('注册')
},
add:function(counter){
//this表示当前的vue,我们通过this.total来获取data中的变量
this.total+= counter
alert(this.total)
}
}
})
</script>
</html>
v-model
双向绑定
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<!-- 导入vue-->
<script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
</head>
<body>
<!--定义一个标签给id -->
<div id="app">
<span>{{ message }}</span>
<hr>
<table>
<tr>
<td>用户名</td>
<td><input type="text" name="username" v-model="username"></td>
</tr>
<tr>
<td>密码</td>
<td><input type="password" name="password1" v-model="password1"></td>
</tr>
<tr>
<td>确认密码</td>
<td><input type="password" name="password2" v-model="password2"></td>
</tr>
<tr>
<td>性别</td>
<td><input type="radio" name="sex" value="boy" v-model="sex">男
<input type="radio" name="sex" value="girl" v-model="sex">女</td>
</tr>
<tr><td>爱好</td>
<td>
足球 <input type="checkbox" name="like" value="足球" v-model="like">
篮球 <input type="checkbox" name="like" value="篮球" v-model="like">
兵乓球<input type="checkbox" name="like" value="兵乓球" v-model="like">
</td>
</tr>
</table>
<button v-on:click="register">注册</button>
</div>
</body>
<!--创建vue实例-->
<script type="text/javascript">
var vm = new Vue({
//接管标签
el: '#app',
//绑定数据
data: {
message: 'hello',
username:'',
password1:'',
password2:'',
sex:'',
like:[]
},
methods:{
register:function(){
alert(this.username+this.password1+this.password2+this.sex+this.like)
}
}
})
</script>
</html>
todolist 案例
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<!-- 导入vue-->
<script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
</head>
<body>
<!--定义标签-->
<div id="app">
<span>{{ message }}</span>
<input type="text" name="todoitem" v-model="newitems">
<button @click="add">添加</button>
<hr>
<ul>
<li v-for="(item,index) in items">
<a href="javascript:;" @click="up(index)">↑</a>
{{ item}}
<a href="javascript:;" @click="deleteitem(index)">删除</a>
<a href="javascript:;" @click="down(index)">↓</a>
</li>
</ul>
</div>
</body>
<!--创建vue实例-->
<script type="text/javascript">
var vm = new Vue({
//接管标签
el: '#app',
//绑定数据
data: {
message: 'hello',
items:['学习html','学习Django','学习MySQL'],
newitems:''
},
//绑定事件
methods:{
add:function (){
this.items.push(this.newitems),
this.newitems=''
},
deleteitem:function(index){
this.items.splice(index,1);
},
up:function(index){
// 获取当前元素
current = this.items[index]
// 先把当前元素删除
this.items.splice(index,1)
// 在添加,添加的时候索引-1
this.items.splice(index-1,0,current)
},
down:function(index){
// 获取当前元素
current = this.items[index]
// 先把当前元素删除
this.items.splice(index,1)
// 在添加,添加的时候索引-1
this.items.splice(index+1,0,current)
}
}
})
</script>
</html>
es6语法
let只能在里边用
var 可以在外面用
const:const声明一个只读的常量。一旦声明,常量的值就不能改变。
es5的对象
var person = {
name:'itcast',
age:13,
say:function(){
alert('hello')
}
}
person.say()
es6的对象
//定义变量
var name='itcast';
var age=13;
//创建对象
var person = {
name,
age,
say:function(){
alert('hello');
}
};
//调用
person.say()
箭头函数
作用:
定义函数新的方式
//无参数,无返回值
var say = ()=> {
alert('我是无参数无返回值函数');
}
//有参数,无返回值
var eat = food => {
alert('我喜欢吃'+food);
}
//有参数,有返回值
var total = (num1,num2) => {
return num1+num2;
}
改变this的指向
如果层级比较深的时候, this的指向就变成了window, 这时候就可以通过箭头函数解决这个指向的问题
var person = {
name:'itcast',
age:13,
say:function(){
alert('my name is ' + this.name);
}
}
//调用
person.say()
生命周期
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<!-- 开发环境版本,包含了有帮助的命令行警告 -->
<script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
</head>
<body>
<div id="app">
{{ message }}
</div>
</body>
<script>
var vm = new Vue({
el: '#app',
data: {
message: 'Hello Vue!'
},
//生命周期的钩子(函数)没有在methods
beforeCreate:function(){
console.log('beforeCreate')
},
created:function(){
console.log('created')
},
beforeMount:function(){
console.log('beforeMount')
},
mounted:function(){
console.log('mounted')
},
beforeDestroy:function(){
console.log('beforeDestroy')
},
destroyed:function(){
console.log('destroyed')
}
})
</script>
</html>
axios发送ajax
vue的大胡子语法和django和flask模板语法冲突
delimiters:['[[',']]']
我们使用Vue的js发送get和post请求,请求我们用django框架进行解析返回渲染页面
首先我们创建一个django项目,创建一个app,注册使用,配置url,书写view,书写Vue
这里就不展示太多了,
View代码如下:
import json
from django.http import JsonResponse
from django.shortcuts import render
# Create your views here.
from django.views import View
class LoginView(View):
def get(self, request):
return render(request, 'login.html')
def post(self, request):
pass
class ReceView(View):
def get(self, request):
data = request.GET
username = data.get('username')
password = data.get('password')
return JsonResponse({'info':{'username':username,'password':password}})
def post(self, request):
data = json.loads(request.body.decode())
username = data.get('username')
password = data.get('password')
return JsonResponse({'info': {'username': username, 'password': password}})
URL配置
from django.conf.urls import url
from book.views import *
urlpatterns = [
url(r'^login/',LoginView.as_view()),
url(r'^rece/',ReceView.as_view()),
]
Vue代码:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
<!-- 开发环境版本 -->
<script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
<!-- 导入axios -->
<script src="https://unpkg.com/axios/dist/axios.min.js"></script>
</head>
<body>
<div id="app">
[[ message ]]
<hr>
[[ username ]]
<button @click="login">登录</button>
<button @click="login1">post</button>
</div>
</body>
<script type="text/javascript">
var vm = new Vue({
el:'#app',
delimiters:["[[","]]"],
data:{
message:'hello Vue!',
username:''
},
methods:{
login:function(){
var url = 'http://127.0.0.1:8000/rece/?username=itcast&password=123'
axios.get(url).then((response)=>{
console.log(response.data.info.username)
this.username = response.data.info.username
}).catch((error)=>{
console.log(error)
})
},
login1:function(){
var url = 'http://127.0.0.1:8000/rece/'
axios.post(url,{"username":'itheima','password':'123'})
.then((response)=>{
console.log(response.data.info.username)
this.username = response.data.info.username
}).catch((error)=>{
console.log(error)
})
}
}
})
</script>
</html>
get效果:
post效果: