夜间模式的开启与关闭，父模板的制作

1.夜间模式的开启与关闭

放置点击的按钮或图片。
定义开关切换函数。
onclick函数调用。

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>调整模式</title>
     <script>
        function mySwitch(){
            var oBody=document.getElementById("myBody");
            var oOnoff=document.getElementById("myOnOff");
            if(oOnoff.src.match("bulbon")){
                oOnoff.src="https://www.runoob.com/images/pic_bulboff.gif";
                oBody.style.background="black";
                oBody.style.color="white";
            }else{
                oOnoff.src="https://www.runoob.com/images/pic_bulbon.gif";
                oBody.style.background="white";
                oBody.style.color="black";
            }
        }
    </script>

</head>

<body id="myBody">
<img id="myOnOff" onclick="mySwitch()" src="https://www.runoob.com/images/pic_bulbon.gif"　height="50" width="50px">
<script> document.write(Date())
</script><br>
<h2>广州商学院欢迎你！</h2>
</body>
</html>

2.父模板的制作

制作网站网页共有元素的父模板html，包括顶部导航，中间区块划分，底部导航，底部说明等。
汇总相关的样式形成独立的css文件。
汇总相关的js代码形成独立的js文件。
形成完整的base.html+css+js

html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <link rel="stylesheet" type="text/css" href="base.css">
    <script src="base.js"></script>
<base href="http://i1.sinaimg.cn/dy/weather/main/index14/007/icons_32_yl/"target="_blank">
</head>
<body id="myBody">
<div class="clearfloat">


     <nav >
         <img src="w_02_08_00.png" >
         <a href="http://www.gzcc.cn/">首页</a>
         <a href="">下载</a>
         <a href="">图书馆</a>
         <a href="">意见反馈</a>
         <input type="text" name="search">
         <button type="submit">搜索</button>
         <a href="{{ url_for('login') }}">登录</a>
         <a href="{{ url_for('zhuce') }}">注册</a>
         <a href="" >联系我们</a>
<img id="myOnOff" onclick="mySwitch()" src="http://www.runoob.com/images/pic_bulbon.gif" width="20px";>
     </nav><hr>

</div>

<br>

<br>
<br>
<br><br>
<h1>
    广州商学院欢迎你!
</h1>
<br><br>
<h1>
    活力广商，筑梦远航！
</h1>
<br><br><br>

        <div id="footer" style="background-color: lightskyblue;clear: both;text-align: center;"></div>
    <div class="desc" >
        <hr>
        <div class="img" >
            <a href="http://www.gzcc.cn/">
                <img src="https://timgsa.baidu.com/timg?image&amp;quality=80&amp;size=b9999_10000&amp;sec=1508497686486&amp;di=e2ccca98fa05f9473c84f73db141ad88&amp;imgtype=0&amp;src=http%3A%2F%2Fpic1.win4000.com%2Fwallpaper%2F7%2F57ac36088f69c.jpg" width="20px">
            </a>
            <div><a href="http://www.gzcc.cn/">数字广商</a></div>
        </div>

        <div class="img">
            <a href="http://www.gzcc.cn/">
                <img src="https://timgsa.baidu.com/timg?image&amp;quality=80&amp;size=b9999_10000&amp;sec=1508497686476&amp;di=50b7102b085d85e015eff1b2d31436ea&amp;imgtype=0&amp;src=http%3A%2F%2Fimg5.xiazaizhijia.com%2Fwalls%2F20150803%2F1440x900_96ae2cb132cbe37.jpg"></a>
                <div><a href="http://www.gzcc.cn/">视频校园</a></div>
        </div>

        <div class="img" class="clearfloat" class="img-hover">
            <a href="http://www.gzcc.cn/">
                <img src="https://timgsa.baidu.com/timg?image&amp;quality=80&amp;size=b9999_10000&amp;sec=1508498137537&amp;di=82dbcda3618e2dfd61810d2fb0daf202&amp;imgtype=0&amp;src=http%3A%2F%2Fpic1.win4000.com%2Fwallpaper%2F1%2F5754d121da01d.jpg"></a>
                <div><a href="http://www.gzcc.cn/">画说校园</a></div>
        </div>

        <div class="img">
            <a href="http://www.gzcc.cn/">
                <img src="https://timgsa.baidu.com/timg?image&amp;quality=80&amp;size=b9999_10000&amp;sec=1508498264263&amp;di=55e6cb21f27b29f83d3c9ff9a73b3bae&amp;imgtype=0&amp;src=http%3A%2F%2Fwww.zcool.com.cn%2Fcommunity%2F037b9a359147e96b5b3086ed42c6bee.jpg" width="80px"></a>
                <div><a href="http://www.gzcc.cn/">全景校园</a></div>


 </div>
        </div>
<footer>
 <div class="footer_box">
     Copyright © 2017 广州商学院 All Rights Reserved　
 </div>
 </footer>
</body>
</html>

function mySwitch() {
            var oBody=document.getElementById("myBody");
            var oOnoff=document.getElementById("myOnOff");
            if(oOnoff.src.match("bulbon")){
                oOnoff.src="http://www.runoob.com/images/pic_bulboff.gif";
                oBody.style.background="black";
                oBody.style.color="white";
            }else {
                 oOnoff.src="http://www.runoob.com/images/pic_bulbon.gif";
                oBody.style.background="white";
                oBody.style.color="black";
            }

        }

css

h1{
    align-content: center;
    size: 800px;
   }
img{
            width: 20px;

        }
       div .img{
            width: 250px;
           height: 200px;
            border: 1px solid #eeeeee;
            float: left;
            margin: 15px;
        }
        div.img img{
            width: 100%;
            height: 80%;
        }
        div.desc{
            text-align: center;
            padding: 15px;
        }
        div.img:hover{
            border: 1px solid yellow;
        }
        .clearfloat{
            clear: both;
        }
       footer{
        position: fixed;
        bottom:0;
         width:100%;
       }

       footer .footer_box{
        background-color: cyan;
        padding: 10px;
       color : #FFFFFF;
        text-align: center;
       }

 nav{
    position:fixed;
    top:0px;
    height: 45px;
    background-color: cyan;
    border-bottom:1px solid #DDDDDD;
    width:100%;
 }
 .clearfloat {
     clear: both;
 }