我生成了一个由Dreamweaver为HTML5提供的默认模板。这是http://jsfiddle.net/9XFEB/。我想将页眉和页脚更改为全宽。如果我给自动财产，页脚就会消失。帮我看看我错过了什么。
<body>
<div class="container">
<header>
<a href="#"><img src="" alt="Insert Logo Here" width="180" height="90" id="Insert_logo" style="background-color: #C6D580; display:block;" /></a>
</header>
<div class="sidebar1">
<ul class="nav">
<li><a href="#">Link one</a></li>
<li><a href="#">Link two</a></li>
<li><a href="#">Link three</a></li>
<li><a href="#">Link four</a></li>
</ul>
<aside>
<p> The above links demonstrate a basic navigational structure using an unordered list styled with CSS. Use this as a starting point and modify the properties to produce your own unique look. If you require flyout menus, create your own using a Spry menu, a menu widget from Adobe's Exchange or a variety of other javascript or CSS solutions.</p>
<p>If you would like the navigation along the top, simply move the ul to the top of the page and recreate the styling.</p>
</aside>
<!-- end .sidebar1 --></div>
<article class="content">
<h1>Instructions</h1>
<section>
<h2>How to use this document</h2>
<p>Be aware that the CSS for these layouts is heavily commented. If you do most of your work in Design view, have a peek at the code to get tips on working with the CSS for the fixed layouts. You can remove these comments before you launch your site. To learn more about the techniques used in these CSS Layouts, read this article at Adobe's Developer Center - <a href="http://www.adobe.com/go/adc_css_layouts">http://www.adobe.com/go/adc_css_layouts</a>.</p>
</section>
<section>
<h2>Clearing Method</h2>
<p>Because all the columns are floated, this layout uses a clear:both declaration in the footer rule. This clearing technique forces the .container to understand where the columns end in order to show any borders or background colors you place on the .container. If your design requires you to remove the footer from the .container, you'll need to use a different clearing method. The most reliable will be to add a <br class="clearfloat" /> or <div class="clearfloat"></div> after your final floated column (but before the .container closes). This will have the same clearing effect. </p>
</section>
<section>
<h2>Logo Replacement</h2>
<p>An image placeholder was used in this layout in the header where you'll likely want to place a logo. It is recommended that you remove the placeholder and replace it with your own linked logo. </p>
<p> Be aware that if you use the Property inspector to navigate to your logo image using the SRC field (instead of removing and replacing the placeholder), you should remove the inline background and display properties. These inline styles are only used to make the logo placeholder show up in browsers for demonstration purposes. </p>
<p>To remove the inline styles, make sure your CSS Styles panel is set to Current. Select the image, and in the Properties pane of the CSS Styles panel, right click and delete the display and background properties. (Of course, you can always go directly into the code and delete the inline styles from the image or placeholder there.)</p>
</section>
<!-- end .content --></article>
<aside>
<h4>Backgrounds</h4>
<p>By nature, the background color on any block element will only show for the length of the content. If you'd like a dividing line instead of a color, place a border on the side of the .content block (but only if it will always contain more content).</p>
</aside>
<footer>
<p>This footer contains the declaration position:relative; to give Internet Explorer 6 hasLayout for the footer and cause it to clear correctly. If you're not required to support IE6, you may remove it.</p>
<address>
Address Content
</address>
</footer>
<!-- end .container --></div>
</body>
答案 0 :(得分：6)
您可以为header和footer 添加css样式，如下所示：
header {
width:100%;
height:20%; //your desired height
position:absolute;
top:0;
left:0;
background-color:blue;
}
footer{
width:100%;
height:20%; //your desired height
position:absolute;
bottom:0;
left:0;
background-color:blue;
}
另一种方法是将页眉，页脚和正文分成三个不同的div：
<html>
<head></head>
<body>
<div id="body">
<div id="header">your header content</div>
<div id="bodycontainer">your body content</div>
<div id="footer">your footer content</div>
</div>
</body>
</html>
要使用页面的整个宽度显示页眉和页脚，请使用此CSS：
#body
{
width:100%;
height:100%; // the desired height
position:absolute;
top:0;
left:0;
}
#header
{
width:100%;
height:20%; // the desired height
position:absolute;
top:0;
left:0;
background-color:blue;
}
#footer
{
width:100%;
height:20%; // the desired height
position:absolute;
bottom:0;
left:0;
background-color:blue;
}
标题位于页面顶部，页脚位于底部。两者都使用整个屏幕宽度。
检查这个小提琴：
答案 1 :(得分：2)