1、添加占位元素，缺点：增加了不必要的多余元素，影响语义性
html代码
1 <body> 2 <div class="header"> 3 </div> 4 5 <!-- header占位元素 --> 6 <div class="header-place"></div> 7 <!-- header占位元素-end --> 8 9 <div class="container"> 10 </div> 11 12 <!-- footer占位元素 --> 13 <div class="footer-place"></div> 14 <!-- footer占位元素-end --> 15 16 <div class="footer"> 17 </div> 18 </body>
scss(sass)代码
1 $header_height:4rem; 2 $footer_height:5rem; 3 4 .header{ 5 width: 100%; 6 height: $header_height; 7 line-height: $header_height; 8 position:fixed; 9 z-index:999; 10 } 11 12 .header-place{ 13 width: 100%; 14 height: $header_height; 15 line-height: $header_height; 16 } 17 18 .footer{ 19 width: 100%; 20 height: $footer_height; 21 position: fixed; 22 z-index:999; 23 } 24 25 .footer-place{ 26 width: 100%; 27 height: $footer_height; 28 }
2、使用伪类
1 body:before{ 2 width: 100%; 3 height: $header_height; 4 line-height: $header_height; 5 display: block; 6 content: ''; 7 } 8 9 body:after{ 10 width: 100%; 11 height: $footer_height; 12 line-height: $footer_height; 13 display: block; 14 content: ''; 15 }