CSS快速入门学习三
一、CSS背景控制
可以控制元素的的背景，大概有以下属性
background-color background-image background-repeat background-attachment background-position
1.控制背景色
例如：
<html>
<head>
<style type="text/css">
body
{
background-color:#b0c4de;
}
</style>
</head>
<body>
<h1>My CSS web page!</h1>
<p>Hello world! This is a W3Schools.com example.</p>
</body>
</html>
效果：
颜色还可以用其他方式表示，如："red","rgb(255,0,0)","#ff0000"
<html> <head> <style type="text/css"> h1 { background-color:#6495ed; } p { background-color:#e0ffff; } div { background-color:#b0c4de; } </style> </head> <body> <h1>CSS background-color example!</h1> <div> This is a text inside a div element. <p>This paragraph has it's own background color.</p> We are still in the div element. </div> </body> </html>
2.控制背景图
<html>
<head>
<style type="text/css">
body {background-image:url('paper.gif')}
</style>
</head>
<body>
<h1>Hello World!</h1>
</body>
</html>
3.背景重复（如何需要在页面上对背景图像进行平铺，可以使用background-repeat属性）
普通效果
<html>
<head>
<style type="text/css">
body
{
background-image:url('gradient2.png');
}
</style>
</head>
<body>
<h1>Hello World!</h1>
</body>
</html>
平铺效果 <html> <head> <style type="text/css"> body { background-image:url('gradient2.png'); background-repeat:repeat-x; } </style> </head> <body> <h1>Hello World!</h1> </body> </html>
4.背景定位
可以用back-ground-position属性改变图像在背景中的位置。
<html> <head> <style type="text/css"> body { background-image:url('img_tree.png'); background-repeat:no-repeat; } </style> </head> <body> <h1>Hello World!</h1> <p>W3Schools background image example.</p> <p>The background image is only showing once, but it is disturbing the reader!</p> </body> </html>
只显示一张图片，如果 去除 background-repeat:no-repeat;
就显示多张图片。
图片置顶，靠右
简写
<html>
<head>
<style type="text/css">
body
{
background:#ffffff url('img_tree.png') no-repeat top right;
margin-right:200px;
}
</style>
</head>
<body>
<h1>Hello World!</h1>
<p>Now the background image is only show once, and positioned away from the text.</p>
<p>In this example we have also added a margin on the right side, so the background image will never disturb the text.</p>
</body>
</html>
