居中 line-hight 是上下
text-line 是左右
实现一个返回顶部的功能:
1 先写好CSS
2 写动作JS
写一个悬浮菜单:
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Title</title> <style> .pg-header{ margin: 0 auto; height: 48px; width:980px; background-color: aquamarine; color: coral; position: fixed; top: 0; left: 20px; right: 20px; line-height: 48px; text-align: center; } .pg-body{ margin: 0 auto; background-color: #dddddd; width:980px; height: 5000px; margin-top: 50px; } </style> </head> <body> <div class="pg-header">此处为菜单</div> <div class="pg-body">此处为内容</div> </body> </html>
效果:
上下滚动菜单始终固定在顶部
实现一个点赞按钮的效果:
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Title</title> </head> <body> <div style="position: relative;width: 500px;height: 200px;border: 1px solid red; margin: 0 auto;"> <div style="position: absolute;left: 0;bottom: 0;width: 50px;height: 50px;background-color: aquamarine"></div> </div> <div style="position: relative;width: 500px;height: 200px;border: 1px solid red; margin: 0 auto;"> <div style="position: absolute;right: 0;top: 0;width: 50px;height: 50px;background-color: aquamarine"></div> </div> </body> </html>
效果:
实现一个遮罩层,就是平时的弹出选择框,即模态框:
加透明度:
opacity 设置遮罩层的透明度 0-1 的范围
三层
设置一个值,谁的大谁在上面:
z-index
实践:
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Title</title> </head> <body> <div style="background-color: white; /*display: none;*/ z-index: 10; position: fixed; height: 400px; width: 500px; top: 50%; left: 50%; margin-left: -250px; margin-top: -200px; border: 1px brown; "> <div style="display: inline">姓名</div><input type="text"/> <div style="display: inline">密码</div><input type="text"/> </div> <div style="background-color: blue; /*display: none;*/ position: fixed; z-index: 9; top:0; bottom: 0; left: 0; right: 0; opacity: 0.5;"></div> <div style="height: 5000px;background-color: coral;"> hehhehhehe</div> </body> </html>
效果:
图片的问题:
overflow
可以设置隐藏或者自动生成滚动条
设置上右下左的间隔:
伪类:
鼠标移到后应用:
当鼠标移到当前标签上时,就会使得下面的css生效
hover
实践:
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Title</title> <style> .pg-header{ position: fixed; /* 设置为固定位置*/ right: 0; /*距离右边0*/ left: 0; /*距离左边0*/ top: 0; /*距离上边0*/ height: 48px; /*高度为48像素*/ background-color: #2459a2; /*背景颜色*/ line-height: 48px; /*设置上下居中,和高度一样才能居中*/ } .pg-body{ margin-top: 50px; /*设置距离顶部50像素,避免menu挡住body*/ } .w{ width: 980px; /*全局宽度 980像素*/ margin: 0 auto; /*自动居中*/ } .pg-header .menu{ display: inline-block; /*设置标签为行内块级混合标签,可以设置高度和宽度*/ padding: 0 10px 0 10px; /*设置标签上下左右的距离*/ color: white; /*字体颜色*/ } .pg-header .menu:hover{ /*此属性是当鼠标移动到此时应用*/ background-color: dodgerblue; /*背景颜色*/ } </style> </head> <body> <div class="pg-header"> <div class="w"> <a class="logo">LOGO</a> <a class="menu">段子</a> <a class="menu">1024</a> <a class="menu">42区</a> </div> </div> <div class="pg-body"> <div class="w">ddddd</div> </div> </body> </html>
渐变色 就是一个非常细的图片一直自动堆叠
高度增加 也是自动堆叠
控制图片怎么堆叠,使用下面的
其实图标都是只用一个图,然后通过调整
就能显示一个图片不同的位置
实践:
<body> <div style="height: 100px;"></div> <div style="height: 20px;width:20px;background-image: url(icon_18_118.png);border: 1px solid red"></div> </body>
显示不同位置:
<body> <div style="height: 100px;"></div> <div style="height: 20px; width:20px; background-image: url(icon_18_118.png); background-position-x: 0px; background-position-y: -58px; border: 1px solid red"></div> </body>
相对的位置,如点赞的图案:
有个问题,图片会挡住输入,修改后就好了
实践:
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Title</title> </head> <body> <div class="user-input" style="padding: 5px;"> <div style="display: inline-block;width: 100px;text-align: right;">账号:</div> <div style="display: inline-block;width: 300px;height:30px;position: relative;"> <input type="text" style="height: 30px; width: 270px; padding-right: 30px"></input> <span style="position:absolute; right: 6px; top:10px; background-image: url(user.jpg); height: 16px; width: 16px; display: inline-block"></span> </div> </div> <div class="passwd-input" style="padding: 5px;"> <div style="display: inline-block;width: 100px;text-align: right;">这是密码:</div> <div style="display: inline-block;width: 300px;height:30px;position: relative;"> <input type="text" style="height: 30px; width: 270px; padding-right: 30px"></input> <span style="position:absolute; right: 6px; top:10px; background-image: url(i_pwd.jpg); height: 16px; width: 16px; display: inline-block"></span> </div> </div> </body> </html>
开始 javascript
一门独立的语言
和java没半毛钱关系
helloworld
写代码的位置,两种形式:
1在html 文件中:
2 单独文件,引入到html文件中:
先执行js 从上往下读运行
js没有完成之前 网页就一直等待js完成,这样对用户就不友好
解决办法就是把js放在html尾部
写在body 内部的最下面:
写的时候先写 var
斟酌以后确实是全局,再去掉var
定义函数:
在控制台打印日志:
console.log(1)
根据id找到内容:
获取内容:
获取子列表:
拼接字符串:
做一个滚动条效果:
实践:
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Title</title> <script> function func() { var tag = document.getElementById(‘i1‘); var content = tag.innerText; var f = content.charAt(0); var l = content.substring(1,content.length) var new_content = l + f; tag.innerText = new_content; } setInterval(‘func()‘,500); </script> </head> <body> <div id="i1">欢迎老男孩莅临指导 </div> </body> </html>
效果:
join 添加分隔符
循环:
DOM
做了一个动作就是把文档转换为一个对象
改变数据:
document.getElementById(‘i1‘).innerText = ‘new数据‘
实现模态框:
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Title</title> <style> .hide{ display: none; } .c1{ position: fixed; left: 0; right: 0; top: 0; bottom: 0; background-color: black; opacity: 0.6; z-index: 9; } .c2{ width: 500px; height: 400px; background-color: white; position: fixed; left: 50%; right: 50%; top: 50%; margin-left: -250px; margin-top: -100px; z-index: 10; } </style> </head> <body> <div> <input type="button" value="添加" onclick="ShowModel();"/> </div> <!--遮罩层 --> <div id="i1" class="c1 hide"></div> <!-- 弹出窗--> <div id="i2" class="c2 hide"> <p> <input type="text"/> <input type="text"/> </p> <p> <input type="button" value="取消" onclick="HideModel();"/> <input type="button" value="确定" onclick="HideModel();"/> </p> </div> <script> function ShowModel() { document.getElementById(‘i1‘).classList.remove(‘hide‘) document.getElementById(‘i2‘).classList.remove(‘hide‘) } function HideModel() { document.getElementById(‘i1‘).classList.add(‘hide‘) document.getElementById(‘i2‘).classList.add(‘hide‘) } </script> </body> </html>
效果:
实现一个全选和取消的功能:
分号必须要加,因为线上的时候会把js文件成为一行,必须用分好来断句, 生成一行就是为了节约空间,有专门的压缩工具
实现一个后台管理的简单页面,需要点击菜单显示菜单,可以全选,反选,可以点击有模态框效果:
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>管理</title> <style> .pg-header{ margin: 0 auto; height: 48px; /*width:980px;*/ background-color: #2459a2; color: coral; position: fixed; top: 0; left: 0; right: 0; line-height: 48px; z-index: 10; } .pg-header .logo{ display: inline-block; margin-left: 50px; } .pg-body{ margin-top: 50px; width:1080px; height: 2000px; } .pg-body .menu{ text-align: center; width:200px; border: 1px solid red; padding: 10px; background-color: aquamarine; float: left; margin: 5px; } .pg-body .menu .every-menu{ text-align: center; display: inline-block; border: 1px solid red; width: 180px; height: 50px; margin: 5px; padding: 2px; line-height: 50px; } .pg-body .info{ float: left; margin: 5px; border: 1px solid red; width: 800px; height: 500px; } .pg-body .info .info-menu{ margin: 10px; } .pg-body .info-body{ margin: 5px; /*width: 650px;*/ height: 400px; border: 1px solid red; text-align: center; } .go-header{ position: fixed; bottom:20px; right:20px; width: 80px; height: 80px; background-color: coral; color: white; z-index: 11; cursor: pointer; } .hide{ display: none; } .c1{ position: fixed; left: 0; right: 0; top: 0; bottom: 0; background-color: black; opacity: 0.6; z-index: 9; } .c2{ width: 500px; height: 400px; background-color: white; position: fixed; left: 50%; right: 50%; top: 50%; margin-left: -250px; margin-top: -100px; z-index: 10; } .hide-menu{ display: none; } .item .header{ height: 35px; background-color: #2459a2; color: white; line-height: 35px; } </style> </head> <body> <div class="pg-header"> <a class="logo">LOGO</a> </div> <div class="go-header" onclick="GoTop();"> <img src="back_top.png" alt="美女" title="返回顶部"> </div> <!--遮罩层 --> <div id="i1" class="c1 hide"></div> <!-- 弹出窗--> <div id="i2" class="c2 hide"> <p> <div style="margin: 5px;"> <div style="display: inline-block;width: 60px;text-align: right">IP:</div> <input type="text"/> </div> <div style="margin: 5px;"> <div style="display: inline-block;width: 60px;text-align: right">主机:</div> <input type="text"/> </div> </p> <p> <div style="display: inline-block;width: 200px;text-align: center"> <input type="button" value="取消" onclick="HideModel();"/> <input type="button" value="确定" onclick="HideModel();"/> </div> </p> </div> <div class="pg-body"> <div class="menu"> <div class="item"> <div id=‘m1‘ class="header" onclick="ChangeMenu(‘m1‘);">菜单1</div> <div class="content hide-menu"> <div>内容1</div> <div>内容1</div> <div>内容1</div> </div> </div> <div class="item"> <div id=‘m2‘ class="header" onclick="ChangeMenu(‘m2‘);">菜单2</div> <div class="content hide-menu"> <div>内容2</div> <div>内容2</div> <div>内容2</div> </div> </div> <div class="item"> <div id=‘m3‘ class="header" onclick="ChangeMenu(‘m3‘);">菜单3</div> <div class="content hide-menu"> <div>内容3</div> <div>内容3</div> <div>内容3</div> </div> </div> <div class="item"> <div id=‘m4‘ class="header" onclick="ChangeMenu(‘m4‘);">菜单4</div> <div class="content hide-menu"> <div>内容4</div> <div>内容4</div> <div>内容4</div> </div> </div> </div> <div class="info"> <div class="info-menu"> <input type="button" value="全选" onclick="CheckAll();"> </input> <input type="button" value="取消" onclick="CancleAll();"> </input> <input type="button" value="反选" onclick="ReCheckAll();"> </input> <input type="button" value="添加" onclick="ShowModel();"> </input> </div> <div class="info-body"> <div> <table> <thead> <tr> <td>选择</td> <td>主机</td> <td>IP</td> <td>备注</td> </tr> </thead> <tbody id="tb"> <tr> <td><input type="checkbox"/></td> <td>web101</td> <td>192.168.8.5</td> <td></td> </tr> <tr> <td><input type="checkbox"/></td> <td>web102</td> <td>192.168.8.6</td> <td></td> </tr> <tr> <td><input type="checkbox"/></td> <td>web103</td> <td>192.168.8.7</td> <td></td> </tr> <tr> <td><input type="checkbox"/></td> <td>web104</td> <td>192.168.8.8</td> <td></td> </tr> <tr> <td><input type="checkbox"/></td> <td>web105</td> <td>192.168.8.9</td> <td></td> </tr> </tbody> </table> </div> </div> </div> <div style="clear: both;"></div> </div> <script> function CheckAll() { var tbody = document.getElementById(‘tb‘); var tr_list = tbody.children; for (var i = 0; i < tr_list.length; i++) { var curren_tr = tr_list[i]; var checkbox = curren_tr.children[0].children[0]; checkbox.checked = true; } } function CancleAll() { var tbody = document.getElementById(‘tb‘); var tr_list = tbody.children; for (var i = 0; i < tr_list.length; i++) { var curren_tr = tr_list[i]; var checkbox = curren_tr.children[0].children[0]; checkbox.checked = false; } } function ReCheckAll() { var tbody = document.getElementById(‘tb‘); var tr_list = tbody.children; for (var i = 0; i < tr_list.length; i++) { var curren_tr = tr_list[i]; var checkbox = curren_tr.children[0].children[0]; if (checkbox.checked) { checkbox.checked = false; }else{ checkbox.checked = true; } } } function GoTop() { document.body.scrollTop = 0; } function ShowModel() { document.getElementById(‘i1‘).classList.remove(‘hide‘) document.getElementById(‘i2‘).classList.remove(‘hide‘) } function HideModel() { document.getElementById(‘i1‘).classList.add(‘hide‘) document.getElementById(‘i2‘).classList.add(‘hide‘) } function ChangeMenu(nid){ var current_header = document.getElementById(nid); var item_list = current_header.parentElement.parentElement.children; for(var i=0;i<item_list.length;i++){ var current_item = item_list[i]; current_item.children[1].classList.add(‘hide-menu‘); } current_header.nextElementSibling.classList.remove(‘hide-menu‘); } </script> </body> </html>
效果: