Vue基础之表单控制 ,v-model进阶,箭头函数,JS循环

发布时间 2023-06-05 20:13:11作者: 岳宗柯

一、表单控制

1.checkbox选中

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <script src="/static/jquery.min.js"></script>
    <link rel="stylesheet" href="/static/bootstrap-3.4.1-dist/css/bootstrap.min.css">
    <script src="/static/bootstrap-3.4.1-dist/js/bootstrap.min.js"></script>
    <title>Title</title>
    <script src="./vue/vue.js"></script>
</head>
<body>
<div id="app">
<h1>checkbox单选</h1>
    <p>用户名: <input type="text" v-model="username" placeholder="请输入用户名:"></p>
    <p>密码: <input type="password" v-model="password" placeholder="请输入密码:"></p>
    <p>记住密码: <input type="checkbox" v-model="remember"></p>
    <hr>
    用户名:{{username}}&#45;&#45;&ndash;&gt;密码:{{password}}&#45;&#45;&ndash;&gt; {{remember}}
</div>
</body>
<script>
    var vm = new Vue({
        el:'#app',
        data:{
            username:'',
            password:'',
            remember:false,
        }
    })
</script>
</html>

image
img

2.radio单选

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <script src="/static/jquery.min.js"></script>
    <link rel="stylesheet" href="/static/bootstrap-3.4.1-dist/css/bootstrap.min.css">
    <script src="/static/bootstrap-3.4.1-dist/js/bootstrap.min.js"></script>
    <title>Title</title>
    <script src="./vue/vue.js"></script>
</head>
<body>
<div id="app">
<h1>radio单选</h1>
      <input type="radio" v-model="gender" value="男">男
    <input type="radio" v-model="gender" value="女">女
    <input type="radio" v-model="gender" value="保密">保密
    <br><br>您选择的性别:{{gender}}
</div>
</body>
<script>
    var vm = new Vue({
        el:'#app',
        data:{
            gender: ''
        }
    })
</script>
</html>
img

3、checkbox多选

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <script src="/static/jquery.min.js"></script>
    <link rel="stylesheet" href="/static/bootstrap-3.4.1-dist/css/bootstrap.min.css">
    <script src="/static/bootstrap-3.4.1-dist/js/bootstrap.min.js"></script>
    <title>Title</title>
    <script src="./vue/vue.js"></script>
</head>
<body>
<div id="app">
<h1>checkbox多选</h1>
       <input type="checkbox" v-model="hobby" value="篮球">篮球
    <input type="checkbox" v-model="hobby" value="足球">足球
    <input type="checkbox" v-model="hobby" value="棒球">棒球
    <input type="checkbox" v-model="hobby" value="桌球">桌球
    <br><br>您喜欢的球类:{{hobby}}
</div>
</body>
<script>
    var vm = new Vue({
        el:'#app',
        data:{
            hobby:[],
        }
    })
</script>
</html>
img

4.购物车案例 - 结算

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <!-- 最新版本的 Bootstrap 核心 CSS 文件 -->
    <link rel="stylesheet" href="https://cdn.bootcdn.net/ajax/libs/twitter-bootstrap/3.4.1/css/bootstrap.min.css"
          integrity="sha384-HSMxcRTRxnN+Bdg0JdbxYKrThecOKuH5zCYotlSAcp1+c8xmyTe9GYg1l9a69psu" crossorigin="anonymous">
    <script src="./js/vue.js"></script>
</head>
<body>
<div id="app">
    <div class="container-fluid">
        <div class="row">
            <div class="col-md-6 col-md-offset-3">
                <h1 class="text-center">购物车</h1>

                <table class="table table-bordered">
                    <thead>
                    <tr>
                        <th>商品ID</th>
                        <th>商品名</th>
                        <th>商品价格</th>
                        <th>商品数量</th>
                        <th>全选/全不选 <input type="checkbox" v-model="checkAll" @change="handleCheckAll"></th>
                    </tr>
                    </thead>
                    <tbody>
                    <tr v-for="good in good_list">
                        <th scope="row">{{good.id}}</th>
                        <td>{{good.name}}</td>
                        <td>

                            {{good.price}}

                        </td>
                        <td>
                            <button class="btn" @click="handleJian(good)">-</button>
                            {{good.number}}
                            <button class="btn" @click="good.number++">+</button>
                        </td>
                        <td><input type="checkbox" :value="good" v-model="checkGroup" @change="handleChangeOne"></td>
                    </tr>
                    </tbody>
                </table>
                <hr>
                选中了:{{checkGroup}}
                <br>
                {{checkAll}}
                <h3>总价格:{{getPrice()}}</h3>
            </div>


        </div>

    </div>


</div>
</body>
<script>
    var vm = new Vue({
        el: '#app',
        data: {
            good_list: [
                {id: 1, name: '钢笔', price: 12, number: 2},
                {id: 2, name: '脸盆', price: 20, number: 20},
                {id: 3, name: '毛笔', price: 6, number: 9},
                {id: 4, name: '圆珠笔', price: 8, number: 5},
                {id: 5, name: '铅笔', price: 1, number: 3},
            ],
            checkGroup: [],
            checkAll: false
        },
        methods: {
            getPrice() {
                // 1 根据checkGroup选中的,计算
                //  循环checkGroup,拿出价格*数量,累加,最后返回
                var total = 0
                for (item of this.checkGroup) {
                    total += item.number * item.price
                }
                return total
            },
            handleCheckAll() {
                // console.log(this.checkAll)
                // 全选中:对钩都打上,js中得含义是:checkGroup变量满值
                if (this.checkAll) {
                    this.checkGroup = this.good_list  // 全选
                } else {
                    this.checkGroup = []  // 全不选
                }

            },
            handleChangeOne() {
                // 判断 checkGroup的长度,是否等于good_list长度
                if (this.checkGroup.length == this.good_list.length) {
                    this.checkAll = true
                } else {
                    this.checkAll = false

                }

            },
            handleJian(good) {
                if (good.number > 1) {
                    good.number--
                } else {
                    alert('太少了,不能再少了')
                }

            }
        }
    })


</script>
</html>
img

二、v-model进阶

v-model 之 lazy、number、trim

lazy:等待input框的数据绑定时区焦点之后再变化
number:数字开头,只保留数字,后面的字母不保留;字母开头,都保留
trim:去除首位的空格 # trim:去除首位的空格

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="./js/vue.js"></script>
</head>
<body>
<div id="app">
    <h1>lazy修饰符</h1>
    <input type="text" v-model.lazy="username">---->{{username}}
    <h1>number修饰符</h1>
    <input type="text" v-model.number="username1">---->{{username1}}
    <h1>trim修饰符</h1>
    <input type="text" v-model.trim="username2">---->{{username2}}
</div>
</body>
<script>
    var vm = new Vue({
        el: '#app',
        data: {
            username: '',
            username1: '',
            username2: '',
        },
    })
</script>
</html>
img

三、箭头函数

es6 的语法

1 函数写法变简单
2 箭头函数没有自己的this,在箭头函数中使用this,就是它上一层的

1 无参数,无返回值

 var f =function (){
     console.log('我是匿名函数')
 }
 var f = () => {
     console.log('我是匿名函数')
 }
 f()

2 有一个参数,没有返回值 ,可以省略括号

var f = function (name) {
     console.log('我是匿名函数',name)
 }
 var f = name => {
     console.log('我是匿名函数', name)
 }
f('Lqz')

3多个参数,不能省略括号

 var f = (name, age) => {
     console.log('我是匿名函数', name, age)
 }
 f('Lqz', 19)

4多个参数,不能省略括号,一个返回值

var f = (name, age) => {
     return name + 'nb'
 }


// 简写成  省了return和大括号
var f = (name, age) => name + 'nb'
var res=f('Lqz', 19)
 console.log(res)

5 一个参数,一个返回值

 var f = name => name + 'nb'
 var res = f('Lqz')
 console.log(res)

四、补充:JS循环

    var arr = [33, 2, 3, 4, 6, 7, 4]
    // 1 基础for循环
     for (var i = 0; i < arr.length; i++) {
         console.log(arr[i])
     }
    // 2 in的循环(不怎么用),循环出索引
     for (i in arr) {
          console.log(i)
         console.log(arr[i])
     }

    //3 of 循环  es6的语法  循环出value值
    for (i of arr) {
         console.log(i)
     }


    // 4 数组的循环
     arr.forEach(function (value, index) {
         console.log(index, '--', value)
     })

    // 5 jq的循环
     $.each(arr, function (index, value) {
         console.log(index, '--', value)
     })