js基本操作

js操作页面三步骤

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <title>操作页面的三步骤</title>
</head>
<body>
    <h1>操作页面的三步骤</h1>
    <div class="box">
        <h1>box h1</h1>
    </div>
</body>
<script>
    // 1、获取页面标签
    // 2、设置操作的激活条件 - 事件
    // 3、具体的操作方式 - 内容 | 样式 | 事件 | 文档结构

    // 1
    let body = document.querySelector('body');
    let box = document.querySelector('.box');
    // 父级调用选择器方法,只完成自己内部的检索
    let body_h1 = body.querySelector('h1');
    console.log(body_h1);
    let box_h1 = box.querySelector('h1');
    console.log(box_h1);

    // 2
    body_h1.onclick = function () {
        // console.log('你丫点我了')
        // 3
        if (box_h1.style.color != 'red') {
            box_h1.style.color = 'red';
            box_h1.style.backgroundColor = 'orange';
        } else {
            box_h1.style.color = 'black';
            box_h1.style.backgroundColor = 'white';
        }
    }
</script>
</html>

js事件

鼠标事件

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <title>鼠标事件</title>
    <style>
        .box {
            width: 200px;
            height: 200px;
            background-color: pink;
            margin: 0 auto;
        }
    </style>
</head>
<body>
    <div class="box"></div>
</body>
<script>
    let box = document.querySelector('.box');
    // 单击
    box.onclick = function () {
        console.log('单击了', this)
    };
    // 双击
    box.ondblclick = function () {
        console.log('双击了')
    };
    // 右键
    box.oncontextmenu = function () {
        console.log('右键了');
        // 有些事件有系统默认动作,取消默认动作可以返回 false
        return false;
    };
    // 悬浮
    box.onmouseover = function () {
        console.log('悬浮了');
    };
    // 移开
    box.onmouseout = function () {
        console.log('移开了');
    };
    // 移动
    box.onmousemove = function () {
        console.log('移动了');
    };
    // 按下
    box.onmousedown = function () {
        console.log('按下了');
    };
    // 抬起
    box.onmouseup = function () {
        console.log('抬起了');
    };
</script>
</html>

文档事件

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <title>文档事件</title>
    <style>
        body {
            height: 3000px;
        }
    </style>
    <script>
        // 页面加载成功
        window.onload = function () {
            console.log(h1)
        }
    </script>
</head>
<body>
    <h1 id="h1">hhhhh</h1>
</body>
<script>
    let body = document.querySelector('body');
    // 页面滚动事件
    document.onscroll = function (ev) {
        console.log('滚动了');
        // console.log(ev);
        // console.log(window.scrollY);
        if (window.scrollY >= 500) {
            body.style.backgroundColor = 'red';
        } else {
            body.style.backgroundColor = 'white';
        }
    }
</script>
</html>

键盘事件

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <title>键盘事件</title>
</head>
<body>
    <h1>键盘事件</h1>
    <input type="text">
</body>
<script>
    let inp = document.querySelector('input');

    inp.onkeydown = function () {
        console.log('按下')
    };
    inp.onkeyup = function () {
        console.log('抬起')
    }

</script>
</html>

表单事件

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <title>表单事件</title>
    <style>
        /*表单的内外边框*/
        input {
            border: 2px solid pink;
        }
        input:focus {
            outline: 2px solid yellow;
        }
    </style>
</head>
<body>
<form action="">
    <input type="text" name="username">
    <input type="password" name="password">
    <input type="submit" value="登录">
</form>
</body>
<script>
    let form = document.querySelector('form');
    let submit = document.querySelector('[type="submit"]');
    let usr = document.querySelector('[type="text"]');

    // 表单提交事件:表单默认也有提交数据的动作,也可以取消
    form.onsubmit = function () {
        console.log('提交了');
        return false;
    };

    // 获取焦点
    usr.onfocus = function () {
        console.log('获取焦点')
    };

    // 失去焦点
    usr.onblur = function () {
        console.log('失去焦点')
    };

</script>
</html>

事件对象

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <title>事件对象</title>
</head>
<body>
<input type="text" class="inp">
</body>
<script>
    inp = document.querySelector('.inp');
    inp.onkeydown= function (ev) {
        console.log(ev);
        // console.log(ev.keyCode);

        if (ev.keyCode === 13) {
            console.log('回车了')
        }
        if (ev.ctrlKey && ev.keyCode === 13) {
            console.log('消息发送了')
        }
    };

    document.onclick = function (ev) {
        console.log(ev);
        // 鼠标点击点
        console.log(ev.clientX, ev.clientY);
    }
    
</script>
</html>

js操作内容

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <title>内容操作</title>
</head>
<body>
    <h1 class="title">标题</h1>
    <input type="text" class="title">
    <button class="btn">改标题</button>
</body>
<script>
    let h1 = document.querySelector('h1.title');
    let inp = document.querySelector('input.title');
    let btn = document.querySelector('.btn');

    // 内容操作:value | innerText | innerHTML
    btn.onclick = function () {
        // 拿到输入框的内容
        inp_value = inp.value;
        if (inp_value) {
            // inp_value = '';  // 改的只是一个内存变量
            inp.value = '';  // 清空输入框

            // 将内容赋值给h1 innerText | innerHTML
            // console.log(h1.innerText);
            // console.log(h1.innerHTML);
            // 纯文本
            // h1.innerText = inp_value;
            // 文本中的标签会被解析
            h1.innerHTML = inp_value;
        }
    }
</script>
</html>

js操作样式

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <title>样式操作</title>
    <style>
        .box {
            width: 200px;
            height: 200px;
            background-color: pink;
        }
        .sup-box {
            /*width: 400px;*/
            height: 100px;
            background-color: orange;
            border-radius: 50%;
            line-height: 100px;
            text-align: center;
            color: red;
        }
    </style>
</head>
<body>
    <!--<div class="box" style="background-color: deeppink;"></div>-->
    <div class="box">文本</div>
</body>
<script>
    let box = document.querySelector('.box');
    // 需求1:单击获取标签的之前背景颜色
    /*
    box.onclick = function () {
        // 注:this.style 本质操作的是行间式(只能获取和设置行间式)
        // bgColor = this.style.backgroundColor;
        // console.log(bgColor);

        // 注:在内联和外联中书写的样式称之为 计算后样式

        // 注:getComputedStyle 能获取计算后样式,也能获取行间式,但是只读
        // getComputedStyle(标签, 伪类).样式;
        bgColor = getComputedStyle(this, null).backgroundColor;
        console.log(bgColor);
        width = getComputedStyle(this, null).width;
        console.log(width, parseInt(width));

        // 只读,会报错
        // getComputedStyle(this, null).backgroundColor = 'rgb(255, 20, 147)';
    }
    */

    // 需求2:点击修改标签的宽高背景颜色
    /*
    box.onclick = function () {
        this.style.backgroundColor = 'orange';
        this_style = getComputedStyle(this, null);
        // console.log(parseInt(this_style.width) * 2);
        // 宽放大两倍,高缩小两倍
        this.style.width = parseInt(this_style.width) * 2 + 'px';
        this.style.height = parseInt(this_style.height) / 2 + 'px';
    }
    */
    
    // 需求:操作计算后样 - 提取写好计算后样式,通过类名将 js 与 css 建立关联
    box.onclick = function () {
        console.log(this.className);
        // this.className = 'sup-box';

        /*
        if (this.className === 'box') {
            this.className = 'sup-box';
        } else {
            this.className = 'box';
        }
        */
        // 注:有个空格:空格sup-box
        // this.className += ' sup-box';

        if (this.className === 'box') {
            this.className += ' sup-box';
        } else {
            this.className = 'box';
        }
    };
</script>
</html>

页面转跳

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <title>页面转跳</title>
</head>
<body>
    <button class="b1">自我刷新</button>
    <button class="b2">转跳到9</button>
    <button class="b3">ctrl新开转跳到9</button>
</body>
<script>
    window.owen = 'Owen';
    let b1 = window.document.querySelector('.b1');
    // 自我刷新
    b1.onclick = function () {
        // console.log(owen);

        // '' 代表当前页面链接
        // window.location.href = '';
        location.reload();
    };

    let b2 = window.document.querySelector('.b2');
    // 转跳到9*.html
    b2.onclick = function () {
        // 在自身所在标签替换
        window.location.href = '9、样式操作.html';
    };

    // ctrl新开转跳到9
    let b3 = window.document.querySelector('.b3');
    b3.onclick = function (ev) {
        // open('转跳路径', '默认就是_blank')
        if (ev.ctrlKey) {
            window.open('9、样式操作.html');
        } else {
            window.open('9、样式操作.html', '_self');
        }
    }
</script>
</html>

屏幕有滚动条下的两种宽度

去除滚动条剩余的全部宽度

let html = document.querySelector('html');
console.log(html.clientWidth);

不去除滚动条剩余的全部宽度

function getHtmlWidth() {
    let hidden = document.createElement('div');
    hidden.style.width = '100vw';
    html.appendChild(hidden);
    width = parseInt(getComputedStyle(hidden, null).width);
    html.removeChild(hidden);
    return width
}
width = getHtmlWidth();
console.log(width);

案例:动态尺寸

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <title>动态尺寸</title>
    <style>
        body {
            margin: 0;
            height: 3000px;
        }
        .box {
            /*width: 200px;*/
            /*height: 200px;*/
            /*width: 100%;*/

            background-color: orange;
            position: fixed;
            top: 0;
            left: 0;

            min-width: 900px;
            max-width: 1100px;

            width: 90%;
            margin-left: 5%;

            /*vw viewwidth  vh viewheight*/
            /*width: 90vw;*/
            /*margin-left: 5vw;*/
        }
    </style>
</head>
<body>
    <div class="hidden" style="width: 100vw"></div>
    <div class="box"></div>
</body>
<script>
    let html = document.querySelector('html');

    // 去除滚动条的宽度
    console.log(html.clientWidth);

    // 包含滚动条的宽度
    // let hidden = document.querySelector('.hidden');
    // width = parseInt(getComputedStyle(hidden, null).width);
    // console.log(width);

    function getHtmlWidth() {
        let hidden = document.createElement('div');
        hidden.style.width = '100vw';
        html.appendChild(hidden);
        width = parseInt(getComputedStyle(hidden, null).width);
        html.removeChild(hidden);
        return width
    }
    width = getHtmlWidth();
    console.log(width);



    function resizeBox() {
        box_width = parseInt(getComputedStyle(box, null).width);
        box.style.height = box_width / 6 + 'px';
        if (box_width >= 1100) {
            box.style.marginLeft = (html.clientWidth - 1100) / 2 + 'px'
        }
    }

    let box = document.querySelector('.box');
    resizeBox();

    window.onresize = function () {
        resizeBox();
    };
</script>
</html>

posted @ 2019-08-05 21:34  小小咸鱼YwY  阅读(398)  评论(0编辑  收藏  举报