CSS 响应式设计

CSS 响应式设计

Viewport

viewport 是用户网页可视区域

设置Viewport

width：控制viewport 大小，可以指定一个值（600px），或特殊的值，如：device-width为设备的宽度
height：高度
initial-scale：初始缩放比例，也就是页面第一次load时候缩放比例
maximum-scale：允许用户缩放到的最大比例
minimum-scale：允许用户缩放到的最小比例
user-scalable：用户是否可以手动缩放

网格视图

很多网页是按列来布局的，通常是12列，宽度100%，在浏览器窗口大小调整时自动伸缩。

确保所有的HTML 元素都有box-sizing 属性且设置为border-box。

* {box-sizing: border-box; }
12列网格系统可以更好的控制响应式网页

<!DOCTYPE html>
<html>
<head>
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <style>
    * {
        box-sizing: border-box;
    }
    .row:after {
        content: "";
        clear: both;
        display: block;
    }
    [class*="col-"] {
        float: left;
        padding: 15px;
    }
    .col-1 {width: 8.33%;}
    .col-2 {width: 16.66%;}
    .col-3 {width: 25%;}
    .col-4 {width: 33.33%;}
    .col-5 {width: 41.66%;}
    .col-6 {width: 50%;}
    .col-7 {width: 58.33%;}
    .col-8 {width: 66.66%;}
    .col-9 {width: 75%;}
    .col-10 {width: 83.33%;}
    .col-11 {width: 91.66%;}
    .col-12 {width: 100%;}

    html {
        font-family: "Lucida Sans", sans-serif;
    }
    .header {
        background-color: #9933cc;
        color: #ffffff;
        padding: 15px;
    }
    .menu ul {
        list-style-type: none;
        margin: 0;
        padding: 0;
    }
    .menu li {
        padding: 8px;
        margin-bottom: 7px;
        background-color :#33b5e5;
        color: #ffffff;
        box-shadow: 0 1px 3px rgba(0,0,0,0.12), 0 1px 2px rgba(0,0,0,0.24);
    }
    .menu li:hover {
        background-color: #0099cc;
    }
</style>
</head>
<body>

    <div class="header">
        <h1>Chania</h1>
    </div>

    <div class="row">

        <div class="col-3 menu">
            <ul>
                <li>The Flight</li>
                <li>The City</li>
                <li>The Island</li>
                <li>The Food</li>
            </ul>
        </div>

        <div class="col-9">
            <h1>The City</h1>
            <p>Chania is the capital of the Chania region on the island of Crete. The city can be divided in two parts, the old town and the modern city.</p>
            <p>Resize the browser window to see how the content respond to the resizing.</p>
        </div>

    </div>
</body>
</html>

媒体查询

使用@media 查询，可以针对不同的媒体类型定义不同的样式

窗口小于500px，

    @media only screen and (max-width:500px){
        [class*="col-"]{
            width:100%;
        }
    }

横屏

@media only screen and (orientation: landscape) {
        body {
            background-color: lightblue;
        }
    }

图片

添加图片

使用width 属性设置为100%，图片会根据上下范围实现响应式功能。

img { width:100%, height:auto;}

如果设置max-width 属性设置为100%，图片永远不会大于其原始大小

img {max-width:100%; height:auto;}

背景图片

背景-简写属性

背景颜色的简写属性为”background”:

body {background: #fff url('img_tree.png') no-repeat right top;}

当使用简写属性时，属性值的顺序为：

background-color
background-image
background-repeat
background-attachment
background-position

背景图片可以响应调整大小或缩放

如果background-size 属性设置为“contain”，背景图片将按比例自适应内容区域。图片保持其比例不变

div { 
   width: 100%; 
   height: 400px; 
   background-image: url('img_flowers.jpg'); 
   background-repeat: no-repeat; 
   background-size: contain; 
   border: 1px solid red; 
}

如果background-size 属性设置为 “100% 100%”，背景图片将延展覆盖整个区域（I love this）

div { 
   width: 100%; 
   height: 400px; 
   background-image: url('img_flowers.jpg'); 
   background-size: 100% 100%; 
   border: 1px solid red; 
}

如果background-size 属性设置为 “cover”，背景扩展，完全覆盖背景区域，还保持图片的比例，某些部分可能无法显示在背景定位区域
```
div { 
   width: 100%; 
   height: 400px; 
   background-image: url('img_flowers.jpg'); 
   background-size: cover; 
   border: 1px solid red; 
}
```

不同设备显示不同的图片

大尺寸图片可以显示在大屏幕上，但在小屏幕上不能很好显示.没有必要在小屏幕上加载大图片，所以根据不同的设备显示不同的图片

/* For width smaller than 400px: */ 
body { 
    background-image: url('img_smallflower.jpg'); 
} 

/* For width 400px and larger: */ 
@media only screen and (min-width: 400px) { 
    body { 
        background-image: url('img_flowers.jpg'); 
    } 
}

也可以使用min-device-width 代替 min-width 属性，它检测的是设备宽度而不是浏览器宽度，当浏览器大小重置时，图片大小不会改变。

/* 设备小于 400px: */ 
body { 
    background-image: url('img_smallflower.jpg'); 
} 

/* 设备大于 400px (也等于): */ 
@media only screen and (min-device-width: 400px) { 
    body { 
        background-image: url('img_flowers.jpg'); 
    } 
}

HTML 5 picture 元素

在body元素里设置

<picture>
    <source srcset="img_smallflower.jpg" media="(max-width: 400px)">
    <source srcset="img_flowers.jpg">
    <img src="img_flowers.jpg" alt="Flowers">
</picture>

视频

width

当width 属性设置为100%，视频播放器会根据屏幕大小自动调整比例：

<!DOCTYPE html>
<html>
<head>
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <style>
    video {
        width: 100%;
        height: auto;
    }
</style>
</head>
<body>

    <video width="400" controls>
        <source src="/statics/demosource/mov_bbb.mp4" type="video/mp4">
            <source src="/statics/demosource/mov_bbb.ogg" type="video/ogg">
                Your browser does not support HTML5 video.
            </video>


            <p>调整浏览器窗口大小查看视频播放器变化</p>

        </body>
        </html>

max-width属性

如果max-width 属性设置为100%，视频播放器会根据屏幕自动调整比例，但不会超过其原始大小：

video{
    max-width:100%
    height:auto;
}

Bootstrap

来自Twitter，最受欢迎的前端框架之一，基于HTML, CSS, JAVASCRIPT,

它简洁灵活，是的web开发更加快捷

自己实现

<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<style>
* {
    box-sizing: border-box;
}
.row:after {
    content: "";
    clear: both;
    display: block;
}
[class*="col-"] {
    float: left;
    padding: 15px;
}
html {
    font-family: "Lucida Sans", sans-serif;
}
.header {
    background-color: #9933cc;
    color: #ffffff;
    padding: 15px;
}
.menu ul {
    list-style-type: none;
    margin: 0;
    padding: 0;
}
.menu li {
    padding: 8px;
    margin-bottom: 7px;
    background-color :#33b5e5;
    color: #ffffff;
    box-shadow: 0 1px 3px rgba(0,0,0,0.12), 0 1px 2px rgba(0,0,0,0.24);
}
.menu li:hover {
    background-color: #0099cc;
}
.aside {
    background-color: #33b5e5;
    padding: 15px;
    color: #ffffff;
    text-align: center;
    font-size: 14px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.12), 0 1px 2px rgba(0,0,0,0.24);
}
.footer {
    background-color: #0099cc;
    color: #ffffff;
    text-align: center;
    font-size: 12px;
    padding: 15px;
}
/* For mobile phones: */
[class*="col-"] {
    width: 100%;
}
@media only screen and (min-width: 600px) {
    /* For tablets: */
    .col-m-1 {width: 8.33%;}
    .col-m-2 {width: 16.66%;}
    .col-m-3 {width: 25%;}
    .col-m-4 {width: 33.33%;}
    .col-m-5 {width: 41.66%;}
    .col-m-6 {width: 50%;}
    .col-m-7 {width: 58.33%;}
    .col-m-8 {width: 66.66%;}
    .col-m-9 {width: 75%;}
    .col-m-10 {width: 83.33%;}
    .col-m-11 {width: 91.66%;}
    .col-m-12 {width: 100%;}
}
@media only screen and (min-width: 768px) {
    /* For desktop: */
    .col-1 {width: 8.33%;}
    .col-2 {width: 16.66%;}
    .col-3 {width: 25%;}
    .col-4 {width: 33.33%;}
    .col-5 {width: 41.66%;}
    .col-6 {width: 50%;}
    .col-7 {width: 58.33%;}
    .col-8 {width: 66.66%;}
    .col-9 {width: 75%;}
    .col-10 {width: 83.33%;}
    .col-11 {width: 91.66%;}
    .col-12 {width: 100%;}
}
</style>
</head>
<body>

<div class="header">
<h1>Chania</h1>
</div>

<div class="row">
<div class="col-3 col-m-3 menu">
<ul>
<li>The Flight</li>
<li>The City</li>
<li>The Island</li>
<li>The Food</li>
</ul>
</div>

<div class="col-6 col-m-9">
<h1>The City</h1>
<p>Chania is the capital of the Chania region on the island of Crete. The city can be divided in two parts, the old town and the modern city.</p>
</div>

<div class="col-3 col-m-12">
<div class="aside">
<h2>What?</h2>
<p>Chania is a city on the island of Crete.</p>
<h2>Where?</h2>
<p>Crete is a Greek island in the Mediterranean Sea.</p>
<h2>How?</h2>
<p>You can reach Chania airport from all over Europe.</p>
</div>
</div>

</div>

<div class="footer">
<p>Resize the browser window to see how the content respond to the resizing.</p>
</div>

</body>
</html>

使用bootstrap

<!DOCTYPE html>
<html lang="en">
<head>
  <title>Bootstrap Example</title>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <link rel="stylesheet" href="http://apps.bdimg.com/libs/bootstrap/3.3.4/css/bootstrap.min.css">
  <script src="http://apps.bdimg.com/libs/jquery/2.1.4/jquery.min.js"></script>
  <script src="http://apps.bdimg.com/libs/bootstrap/3.3.4/js/bootstrap.min.js"></script>
  <style type="text/css">
  *{
    box-sizing:border-box;
  }
  .row:after{
    content:"";
    clear:both;
    display:block;
  }


  .jumbotron{
    background-color: #9933cc;
    color: #ffffff;
    padding: 15px;
  }

  ul {
    list-style-type: none;
    margin: 0;
    padding: 0;
  }
  li {
    padding: 8px;
    margin-bottom: 7px;
    background-color :#33b5e5;
    color: #ffffff;
    box-shadow: 0 1px 3px rgba(0,0,0,0.12), 0 1px 2px rgba(0,0,0,0.24);
  }
  li:hover {
    background-color: #0099cc;
  }
  .aside {
    background-color: #33b5e5;
    padding: 15px;
    color: #ffffff;
    text-align: center;
    font-size: 14px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.12), 0 1px 2px rgba(0,0,0,0.24);
  }
  .footer {
    background-color: #0099cc;
    color: #ffffff;
    text-align: center;
    font-size: 12px;
    padding: 15px;
  }
</style>
</head>
<body>


  <div class="container">
    <div class="jumbotron">
     <h1>Chania</h1>
   </div>
   <div class="row">

    <div class="col-sm-4">
     <ul>
      <li>The Flight</li>
      <li>The City</li>
      <li>The Island</li>
      <li>The Food</li>
    </ul>
  </div>

  <div class="col-sm-4">
    <h1>The City</h1>
    <p>Chania is the capital of the Chania region on the island of Crete. The city can be divided in two parts, the old town and the modern city.</p>
  </div>

  <div class="col-sm-4">
    <div class="aside">
      <h2>What?</h2>
      <p>Chania is a city on the island of Crete.</p>
      <h2>Where?</h2>
      <p>Crete is a Greek island in the Mediterranean Sea.</p>
      <h2>How?</h2>
      <p>You can reach Chania airport from all over Europe.</p>
    </div>
  </div>

</div>
</div>


<div class="footer">
  <p>Resize the browser window to see how the content respond to the resizing.</p>
</div>

</body>
</html>

在标签内部使用class，可以有多个值如：

<div class="col-3 col-m-3 menu">

CSS响应式