Javascript-web API-day02

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文章目录

- 01-事件监听
- 02-点击关闭广告
- 03-随机点名案例
- 04-鼠标经过或离开事件
- 05-可点击的轮播图
- 06-小米搜索框
- 07-键盘类型事件
- 08-键盘事件-发布评论案例
- 09-focus选择器
- 10-评论回车发布
- 11-事件对象
- 12-trim方法
- 13-环境对象
- 14-回调函数
- 15-tab栏切换

01-事件监听

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <button>点击</button>
  <script>
    // 事件源
    const btn = document.querySelector('button')
    // 时间侦听
    btn.addEventListener('click', function () {
      alert('弹窗')

    })
  </script>
</body>

</html>

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02-点击关闭广告

<!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>Document</title>
  <style>
    .box {
      position: relative;
      width: 1000px;
      height: 200px;
      background-color: pink;
      margin: 100px auto;
      text-align: center;
      font-size: 50px;
      line-height: 200px;
      font-weight: 700;
    }

    .box1 {
      position: absolute;
      right: 20px;
      top: 10px;
      width: 20px;
      height: 20px;
      background-color: skyblue;
      text-align: center;
      line-height: 20px;
      font-size: 16px;
      cursor: pointer;
    }
  </style>
</head>

<body>
  <div class="box">
    我是广告
    <div class="box1">X</div>
  </div>
  <script>
    // 1. 获取事件源
    const box1 = document.querySelector('.box1')
    //  关闭的是大盒子
    const box = document.querySelector('.box')
    // 2. 事件侦听
    box1.addEventListener('click', function () {
      box.style.display = 'none'
    })
  </script>
</body>

</html>

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03-随机点名案例

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    * {
      margin: 0;
      padding: 0;
    }

    h2 {
      text-align: center;
    }

    .box {
      width: 600px;
      margin: 50px auto;
      display: flex;
      font-size: 25px;
      line-height: 40px;
    }

    .qs {

      width: 450px;
      height: 40px;
      color: red;

    }

    .btns {
      text-align: center;
    }

    .btns button {
      width: 120px;
      height: 35px;
      margin: 0 50px;
    }
  </style>
</head>
<!-- 业务分析:
  1点击开始按钮随机抽取数组的一个数据，放到页面中
  2点击结束按钮删除数组当前抽取的一个数据
  3当抽取到最后一个数据的时候，两个按钮同时禁用(写点开始里面，只剩最后一个数据不用抽了)
  核心:利用定时器快速展示，停止定时器结束展示 -->

<body>
  <h2>随机点名</h2>
  <div class="box">
    <span>名字是：</span>
    <div class="qs">这里显示姓名</div>
  </div>
  <div class="btns">
    <button class="start">开始</button>
    <button class="end">结束</button>
  </div>

  <script>
    // 数据数组
    const arr = ['马超', '黄忠', '赵云', '关羽', '张飞']
    // 业务1：开始按钮模块

    // 定时器编号设置为全局变量
    let n = 0
    // 数组下标设置为全局变量
    let random = 0
    const start = document.querySelector('.start')
    const qs = document.querySelector('.qs')
    start.addEventListener('click', function () {
      n = setInterval(function () {
        random = Math.floor(Math.random() * arr.length)
        qs.innerHTML = `${arr[random]}`
      }, 50)

      // 如果数组只剩一个元素：把两个按钮都禁用
      if (arr.length === 1) {
        start.disabled = true
        end.disabled = true

      }

    })
    // 业务2：结束模块
    const end = document.querySelector('.end')
    end.addEventListener('click', function () {
      clearInterval(n)
      arr.splice(random, 1)
    })

  </script>
</body>

</html>

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04-鼠标经过或离开事件

<!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>Document</title>
  <style>
    div {
      width: 200px;
      height: 200px;
      background-color: pink;
    }
  </style>
</head>

<body>
  <div></div>
  <script>
    const div = document.querySelector('div')
    // 鼠标经过
    div.addEventListener('mouseenter', function () {
      console.log(`轻轻的我来了`)
    })
    // 鼠标离开
    div.addEventListener('mouseleave', function () {
      console.log(`轻轻的我走了`)
    })

  </script>
</body>

</html>

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05-可点击的轮播图

<!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>轮播图点击切换</title>
  <style>
    * {
      box-sizing: border-box;
    }

    .slider {
      width: 560px;
      height: 400px;
      overflow: hidden;
    }

    .slider-wrapper {
      width: 100%;
      height: 320px;
    }

    .slider-wrapper img {
      width: 100%;
      height: 100%;
      display: block;
    }

    .slider-footer {
      height: 80px;
      background-color: rgb(100, 67, 68);
      padding: 12px 12px 0 12px;
      position: relative;
    }

    .slider-footer .toggle {
      position: absolute;
      right: 0;
      top: 12px;
      display: flex;
    }

    .slider-footer .toggle button {
      margin-right: 12px;
      width: 28px;
      height: 28px;
      appearance: none;
      border: none;
      background: rgba(255, 255, 255, 0.1);
      color: #fff;
      border-radius: 4px;
      cursor: pointer;
    }

    .slider-footer .toggle button:hover {
      background: rgba(255, 255, 255, 0.2);
    }

    .slider-footer p {
      margin: 0;
      color: #fff;
      font-size: 18px;
      margin-bottom: 10px;
    }

    .slider-indicator {
      margin: 0;
      padding: 0;
      list-style: none;
      display: flex;
      align-items: center;
    }

    .slider-indicator li {
      width: 8px;
      height: 8px;
      margin: 4px;
      border-radius: 50%;
      background: #fff;
      opacity: 0.4;
      cursor: pointer;
    }

    .slider-indicator li.active {
      width: 12px;
      height: 12px;
      opacity: 1;
    }
  </style>
</head>

<body>
  <div class="slider">
    <div class="slider-wrapper">
      <img src="./images/slider01.jpg" alt="" />
    </div>
    <div class="slider-footer">
      <p>对人类来说会不会太超前了？</p>
      <ul class="slider-indicator">
        <li class="active"></li>
        <li></li>
        <li></li>
        <li></li>
        <li></li>
        <li></li>
        <li></li>
        <li></li>
      </ul>
      <div class="toggle">
        <button class="prev">&lt;</button>
        <button class="next">&gt;</button>
      </div>
    </div>
  </div>
  <script>
    // 1. 初始数据
    const sliderData = [
      { url: './images/slider01.jpg', title: '对人类来说会不会太超前了？', color: 'rgb(100, 67, 68)' },
      { url: './images/slider02.jpg', title: '开启剑与雪的黑暗传说！', color: 'rgb(43, 35, 26)' },
      { url: './images/slider03.jpg', title: '真正的jo厨出现了！', color: 'rgb(36, 31, 33)' },
      { url: './images/slider04.jpg', title: '李玉刚：让世界通过B站看到东方大国文化', color: 'rgb(139, 98, 66)' },
      { url: './images/slider05.jpg', title: '快来分享你的寒假日常吧~', color: 'rgb(67, 90, 92)' },
      { url: './images/slider06.jpg', title: '哔哩哔哩小年YEAH', color: 'rgb(166, 131, 143)' },
      { url: './images/slider07.jpg', title: '一站式解决你的电脑配置问题！！！', color: 'rgb(53, 29, 25)' },
      { url: './images/slider08.jpg', title: '谁不想和小猫咪贴贴呢！', color: 'rgb(99, 72, 114)' },
    ]
    //右侧按钮服务：点击图变 字变 颜色变 小圆点变 点击到最后一个之后从新开始
    let i = 0
    const next = document.querySelector('.next')
    const img = document.querySelector('.slider-wrapper img')
    const p = document.querySelector('.slider-footer p')


    next.addEventListener('click', function () {
      i++
      if (i >= sliderData.length) {
        i = 0
      }
      toggle()
    })

    //左侧按钮服务：点击图变 字变 颜色变 小圆点变 点击到最后一个之后从新开始
    const prev = document.querySelector('.prev')
    prev.addEventListener('click', function () {
      i--
      if (i < 0) {
        i = sliderData.length - 1
      }
      toggle()
    })

    // 定时模块
    let timer = setInterval(function () {
      next.click()
    }, 1000)

    // 鼠标经过功能：关闭定时器
    const slider = document.querySelector('.slider')
    slider.addEventListener('mouseenter', function () {
      clearInterval(timer)
    })
    // 鼠标离开：打开定时器
    slider.addEventListener('mouseleave', function () {
      clearInterval(timer)
      timer = setInterval(function () {
        next.click()

      }, 1000)
    })
    // 把重复代码用函数封装起来
    function toggle() {
      img.src = sliderData[i].url
      p.innerHTML = sliderData[i].title
      document.querySelector('.slider-footer').style.backgroundColor = sliderData[i].color
      document.querySelector('.slider-indicator .active').classList.remove('active')
      document.querySelector(`.slider-footer li:nth-child(${i + 1})`).classList.add('active')
    }
  </script>
</body>

</html>

06-小米搜索框

<!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>Document</title>
  <style>
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }

    ul {
      display: none;
      list-style: none;
    }

    .mi {
      position: relative;
      width: 223px;
      margin: 100px auto;
    }

    .mi input {
      width: 223px;
      height: 48px;
      padding: 0 10px;
      font-size: 14px;
      line-height: 48px;
      border: 1px solid #e0e0e0;
      outline: none;
    }

    .mi .search {
      border: 1px solid #ff6700;
    }

    .result-list {
      position: absolute;
      left: 0;
      top: 48px;
      width: 223px;
      border: 1px solid #ff6700;
      border-top: 0;
      background: #fff;
    }

    .result-list a {
      display: block;
      padding: 6px 15px;
      font-size: 12px;
      color: #424242;
      text-decoration: none;
    }

    .result-list a:hover {
      background-color: #eee;
    }
  </style>

</head>

<body>
  <div class="mi">
    <input type="search" placeholder="小米笔记本">
    <ul class="result-list">
      <li><a href="#">全部商品</a></li>
      <li><a href="#">小米11</a></li>
      <li><a href="#">小米10S</a></li>
      <li><a href="#">小米笔记本</a></li>
      <li><a href="#">小米手机</a></li>
      <li><a href="#">黑鲨4</a></li>
      <li><a href="#">空调</a></li>
    </ul>
  </div>
  <script>
    const input = document.querySelector('input')
    const ul = document.querySelector('ul')

    // 焦点放置：显示下拉菜单+搜索框变颜色
    input.addEventListener('focus', function () {
      ul.style.display = 'block'
      input.classList.add('search')
    })

    // 焦点离开：下拉菜单不显示
    input.addEventListener('blur', function () {
      ul.style.display = 'none'
      input.classList.remove('search')
    })
  </script>
</body>

</html>

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07-键盘类型事件

![<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <input type="text">
  <script>
    const input = document.querySelector('input')
    input.addEventListener('keydown', function () {
      console.log('jianpan')
    })
    input.addEventListener('keyup', function () {
      console.log('jianpanuo')
    })
  </script>
</body>

</html>](https://i-blog.csdnimg.cn/direct/d238d77d9d294f578d287308f6cc7d65.png)

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08-键盘事件-发布评论案例

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <input type="text" name="" id="">
  <script>
    const input = document.querySelector('input')
    input.addEventListener('input', function () {
      console.log(input.value)
    })
  </script>
</body>

</html>

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09-focus选择器

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    input {
      width: 220px;
      transition: all .3s;
    }

    input:focus {
      width: 300px;
    }
  </style>
</head>

<body>
  <input type="text">
</body>

</html>

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10-评论回车发布

<!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>评论回车发布</title>
  <style>
    .wrapper {
      min-width: 400px;
      max-width: 800px;
      display: flex;
      justify-content: flex-end;
    }

    .avatar {
      width: 48px;
      height: 48px;
      border-radius: 50%;
      overflow: hidden;
      background: url(./images/avatar.jpg) no-repeat center / cover;
      margin-right: 20px;
    }

    .wrapper textarea {
      outline: none;
      border-color: transparent;
      resize: none;
      background: #f5f5f5;
      border-radius: 4px;
      flex: 1;
      padding: 10px;
      transition: all 0.5s;
      height: 30px;
    }

    .wrapper textarea:focus {
      border-color: #e4e4e4;
      background: #fff;
      height: 50px;
    }

    .wrapper button {
      background: #00aeec;
      color: #fff;
      border: none;
      border-radius: 4px;
      margin-left: 10px;
      width: 70px;
      cursor: pointer;
    }

    .wrapper .total {
      margin-right: 80px;
      color: #999;
      margin-top: 5px;
      opacity: 0;
      transition: all 0.5s;
    }

    .list {
      min-width: 400px;
      max-width: 800px;
      display: flex;
    }

    .list .item {
      width: 100%;
      display: flex;
    }

    .list .item .info {
      flex: 1;
      border-bottom: 1px dashed #e4e4e4;
      padding-bottom: 10px;
    }

    .list .item p {
      margin: 0;
    }

    .list .item .name {
      color: #FB7299;
      font-size: 14px;
      font-weight: bold;
    }

    .list .item .text {
      color: #333;
      padding: 10px 0;
    }

    .list .item .time {
      color: #999;
      font-size: 12px;
    }
  </style>
</head>

<body>
  <div class="wrapper">
    <i class="avatar"></i>
    <textarea id="tx" placeholder="发一条友善的评论" rows="2" maxlength="200"></textarea>
    <button>发布</button>
  </div>
  <div class="wrapper">
    <span class="total">0/200字</span>
  </div>
  <div class="list">
    <div class="item" style="display: none;">
      <i class="avatar"></i>
      <div class="info">
        <p class="name">清风徐来</p>
        <p class="text">大家都辛苦啦，感谢各位大大的努力，能圆满完成真是太好了[笑哭][支持]</p>
        <p class="time">2022-10-10 20:29:21</p>
      </div>
    </div>
  </div>

  <script>
    const textarea = document.querySelector('#tx')
    const total = document.querySelector('.total')
    const item = document.querySelector('.item')
    const text = document.querySelector('.text')
    // 文本域获得焦点 字数显示
    textarea.addEventListener('focus', function () {
      total.style.opacity = 1
      // total.value = `${textarea.value.length}/200字`
    })
    // 文本域失去焦点 字数隐藏
    textarea.addEventListener('blur', function () {
      total.style.opacity = 0
    })
    // 检测光标输入事件
    textarea.addEventListener('input', function () {
      // console.log(textarea.value.length)
      total.innerHTML = `${textarea.value.length}/200字`
    })
    // 按下回车发布评论
    textarea.addEventListener('keyup', function (e) {
      // 只有按下的是回车键，才会触发
      if (e.key === 'Enter') {
        if (textarea.value.trim() !== '') {
          // 这个if等价于if(textarea.value.trim())
          // 消除空字符串的bug
          item.style.display = 'block'
          text.innerHTML = textarea.value
        }
        // 回车完成之后清空文本域
        textarea.value = ''
        // 回车完成之后清字数统计 复原
        total.innerHTML = '0/200字'
      }
    })
  </script>
</body>

</html>

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11-事件对象

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <button>点击</button>
  <input type="text">
  <script>
    // const btn = document.querySelector('button')
    // btn.addEventListener('click', function (e) {
    //   console.log(e)

    // })

    const input = document.querySelector('input')
    input.addEventListener('keyup', function (e) {
      console.log(e.key)
      if (e.key === 'Enter') {
        console.log('回车')
      }
    })

  </script>
</body>

</html>

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12-trim方法

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <script>
    const str = '       im a teachr   '
    console.log(str.trim())
    // 去除字符串左右空格
  </script>
</body>

</html>

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13-环境对象

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <!-- 环境对象this:代表着当前函数运行时所处的环境 -->
  <!-- this指向：谁调用this 就指向谁 -->
  <button>按钮</button>
  <script>
    function fn() {
      console.log(this)
      // 这个指向windows
    }
    const button = document.querySelector('button')
    button.addEventListener('click', function () {
      console.log(this)
      // 这个指向button
      button.style.color = 'red'
      // 等价于:this.style.color = 'red'
    })
  </script>
</body>

</html>

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14-回调函数

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <!-- 函数A作为参数传给函数B  A就叫回调函数 -->
  <script>
    function fn() {
      console.log(101)
    }
    setInterval(fn, 1000)
    // fn就是回调函数
  </script>
</body>

</html>

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15-tab栏切换

<!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>tab栏切换</title>
  <style>
    * {
      margin: 0;
      padding: 0;
    }

    .tab {
      width: 590px;
      height: 340px;
      margin: 20px;
      border: 1px solid #e4e4e4;
    }

    .tab-nav {
      width: 100%;
      height: 60px;
      line-height: 60px;
      display: flex;
      justify-content: space-between;
    }

    .tab-nav h3 {
      font-size: 24px;
      font-weight: normal;
      margin-left: 20px;
    }

    .tab-nav ul {
      list-style: none;
      display: flex;
      justify-content: flex-end;
    }

    .tab-nav ul li {
      margin: 0 20px;
      font-size: 14px;
    }

    .tab-nav ul li a {
      text-decoration: none;
      border-bottom: 2px solid transparent;
      color: #333;
    }

    .tab-nav ul li a.active {
      border-color: #e1251b;
      color: #e1251b;
    }

    .tab-content {
      padding: 0 16px;
    }

    .tab-content .item {
      display: none;
    }

    .tab-content .item.active {
      display: block;
    }
  </style>
</head>

<body>
  <div class="tab">
    <div class="tab-nav">
      <h3>每日特价</h3>
      <ul>
        <li><a class="active" href="javascript:;">精选</a></li>
        <li><a href="javascript:;">美食</a></li>
        <li><a href="javascript:;">百货</a></li>
        <li><a href="javascript:;">个护</a></li>
        <li><a href="javascript:;">预告</a></li>
      </ul>
    </div>
    <div class="tab-content">
      <div class="item active"><img src="./images/tab00.png" alt="" /></div>
      <div class="item"><img src="./images/tab01.png" alt="" /></div>
      <div class="item"><img src="./images/tab02.png" alt="" /></div>
      <div class="item"><img src="./images/tab03.png" alt="" /></div>
      <div class="item"><img src="./images/tab04.png" alt="" /></div>
    </div>
  </div>
  <script>
    const as = document.querySelectorAll('.tab-nav li a')

    for (let i = 0; i < as.length; i++) {
      as[i].addEventListener('mouseenter', function () {
        document.querySelector('.tab-nav li .active').classList.remove('active')
        this.classList.add('active')
        document.querySelector('.tab-content .active').classList.remove('active')
        document.querySelector(`.tab-content .item:nth-child(${i + 1})`).classList.add('active')
      })
    }

  </script>
</body>

</html>