03JavaScript程序设计修炼之道_2019-07-02_21-47-36_ 鼠标弹起拖拽、放大镜、mouseenter&mouseleave、

DOCTYPE html>
html lang="en">

head>
    meta charset="UTF-8">
    meta name="viewport" content="width=device-width, initial-scale=1.0">
    meta http-equiv="X-UA-Compatible" content="ie=edge">
    title>Documenttitle>
    style>
        * {
            padding: 0;
            margin: 0;
        }

        .box {
            width: 100px;
            height: 100px;
            
            border: 20px solid gray;
            border-top-width: 30px;
            padding: 12px;
            background-color: blue;
            cursor: move;
            position: absolute;
        }
    style>
head>

body>
    div class="box" id="box">div>
    script>
        var box = document.querySelector("#box");
        box.onmousedown = function(e) {
            var e = e || event;
            // 记住点击div的内部偏移量
            var disx = e.offsetX || e.layerX;
            var disy = e.offsetY || e.layerY;
            document.onmousemove = function(e) {
                var e =  e || event;
                box.style.left = e.pageX - disx + "px"; 
                box.style.top = e.pageY - disy + "px"; 
            }
            // 鼠标弹起  取消拖拽
            document.onmouseup = function() {
                document.onmousemove = null;
            }
        }
    script>
body>

html>

DOCTYPE html>
html>
    head>
        meta charset="UTF-8">
        title>title>
    head>
    style type="text/css">
        *{
            margin: 0;
            padding: 0;
        }
        #box{
            width: 350px;
            height: 350px;
            border: 1px solid #000;
            margin: 200px;
            position: relative;
        }
        #big{
            width: 400px;
            height: 400px;
            border: 1px solid #000;
            overflow: hidden;
            position: absolute;
            top:0;
            left : 360px;
            display: none;
        }
        #mask{
            width: 175px;
            height: 175px;
            background: paleturquoise;
            position: absolute;
            left:0;
            top: 0;
            opacity: 0.3;
            display: none;
            cursor: move;
        }
        #small{
            position: relative;
        }
        #bigImg{
            position: absolute;
            left: 0;
            top: 0;
        }
    style>
    body>
        div id="box" >
            div id="small">
                img src="img/001.jpg" alt="" />
                div id="mask">div>
            div>
            div id="big">
                img src="img/0001.jpg" width="600" height="600" alt="" id="bigImg"/>
            div>
        div>
    body>
    script src="./tool.js">script>
    script>
         var box = $("box");
         var small = $("small");
         var mask = $("mask");
         var big = $("big");
         var bigImg = $("bigImg");
         // 鼠标放入small区域 遮罩层与big显示
         $("small").onmouseenter = function() {
              $("mask").style.display = "block";
              $("big").style.display = "block";  
         }
         // 鼠标离开small区域 遮罩层与big隐藏
         $("small").onmouseleave = function() {
              $("mask").style.display = "none";
              $("big").style.display = "none";  
         }
         // 鼠标在小图区移动
         $("small").onmousemove = function(e) {
              var e = e || event;
              var x = e.pageX - mask.offsetWidth/2 - box.offsetLeft;
              var y = e.pageY - mask.offsetHeight/2 - box.offsetTop;
              // 水平范围 0～box.offsetWidth - mask.offsetWidth
              // 竖直范围 0～box.offsetHeight - mask.offsetHeight
              var maxL = box.offsetWidth - mask.offsetWidth;
              var maxT = box.offsetHeight - mask.offsetHeight
              x = x0?0:(x>maxL?maxL:x);
              y = y0?0:(y>maxT?maxT:y);
              // 设置遮罩层坐标
              mask.style.left = x + "px";
              mask.style.top = y + "px";

              // 对大图进行操作
              // 小图区:大图区 = x:大图片移动的距离
              var bigImgLeft = -x*big.offsetWidth/small.offsetWidth;
              var bigImgTop = -y*big.offsetHeight/small.offsetHeight;
              bigImg.style.left = bigImgLeft + "px";
              bigImg.style.top = bigImgTop + "px";
         }
    script>
html>

DOCTYPE html>
html lang="en">
head>
    meta charset="UTF-8">
    meta name="viewport" content="width=device-width, initial-scale=1.0">
    meta http-equiv="X-UA-Compatible" content="ie=edge">
    title>Documenttitle>
    style>
        #box1 {
            width: 300px;
            height: 300px;
            background-color: red;
        }

        #box2 {
            width: 150px;
            height: 150px;
            background-color: green;
        }
    style>
head>
body>
    div id="box1">
        div id="box2">div>
    div>
    script>
        var box1 = document.querySelector("#box1");
        var num = 0;
        // 触发子元素的mouseover 会冒泡到父亲上
        /*box1.onmouseover = function() {
            num++;
            console.log(num);
        }
        */
        
        // 触发子元素的mouseover 不会冒泡到父亲上
        box1.onmouseenter = function() {
            num++;
            console.log(num);
        }
    script>
body>
html>

DOCTYPE html>
html lang="en">

head>
    meta charset="UTF-8">
    meta name="viewport" content="width=device-width, initial-scale=1.0">
    meta http-equiv="X-UA-Compatible" content="ie=edge">
    title>Documenttitle>
    style>
        * {
            padding: 0;
            margin: 0
        }

        a {
            text-decoration: none;
            color: #000;
        }

        .login-header {
            text-align: center;
            height: 30px;
            line-height: 30px;
            font-size: 24px;
        }

        .login {
            width: 512px;
            height: 280px;
            position: absolute;
            left: 50%;
            top: 50%;
            margin-left: -256px;
            margin-top: -140px;
            background-color: #fff;
            z-index: 9999;
            border: 1px solid #ebebeb;
            box-shadow: 0px 0px 20px #ddd;
            display: none;
        }

        .login-title {
            width: 100%;
            text-align: center;
            height: 40px;
            line-height: 40px;
            font-size: 18px;
            cursor: move;
            margin: 10px 0 0 0;
            position: relative;
        }

        .login-title span {
            position: absolute;
            right: -20px;
            top: -30px;
            background-color: #fff;
            width: 40px;
            height: 40px;
            border-radius: 50%;
        }

        .mask {
            width: 100%;
            height: 100%;
            position: fixed;
            left: 0px;
            top: 0px;
            background-color: #000;
            opacity: 0.3;
            -moz-opacity: 0.3;
            filter: alpha(opacity=30);
            display: none;
        }
    style>
head>

body>
    div class="login-header">a id="login_btn" href="javascript:void(0);">登陆a>div>
    div class="login" id="login">
        div class="login-title" id="loginTitle">
            登陆会员
            span>a id="closeBtn" class="close-btn" href="javascript:void(0);">关闭a>span>
        div>
        div class="login-content">
            div class="login-input">
                label for="">用户名:label>
                input type="text" name="" id="">
            div>
            div class="login-input">
                label for="">密码:label>
                input type="password" name="" id="">
            div>
        div>
        div class="login-button">
            a id="loginBtn" href="javascript:void(0);">登陆a>
        div>
    div>
    div class="mask" id="mask">div>
    script src="./tool.js">script>
    script>
        var login_btn = document.getElementById("login_btn");
        // 显示登陆框与遮罩层
        login_btn.onclick = function () {
            $("mask").style.display = "block";
            $("login").style.display = "block";
            return false;
        }
        // 点击关闭 关闭登陆框与遮罩层
        $("closeBtn").onclick = function () {
            $("mask").style.display = "none";
            $("login").style.display = "none";
        }
        // 拖拽
        $("loginTitle").onmousedown = function(e) {
            var e = e || event;
            var disx = e.pageX - $("login").offsetLeft;
            var disy = e.pageY - $("login").offsetTop;
            document.onmousemove = function(e) {
                var loginX = e.pageX - disx;
                var loginY = e.pageY - disy;
                $("login").style.left = loginX + $("login").offsetWidth/2 + "px";
                $("login").style.top = loginY + $("login").offsetHeight/2 + "px";
            }
            document.onmouseup = function() {
                document.onmousemove = null;
            }
        }
    script>
body>

html>