浮動引發的Bug
浮動的方法
float：left；right；none
浮動的原理
改變元素的排布方式；浮動元素會脫離文檔流。
浮動影響
産生卡頓；浮動的子元素撐不開父元素高度。父元素不設定高度，子元素都浮動；
浮動解決方法
1.給父級也加浮動（這種情況當父級margin:0 auto;時不居中）
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>1.給父級也加浮動(不居中了)</title>
<style>
.parentElement{ width:300px;margin:0 auto;border:10px solid #000;float:left;}
.subElement{ width:200px;height:200px;background:red;float:left;}
</style>
</head>
<body>
<div class="parentElement">
<div class="subElement"></div>
</div>
</body>
</html>
2.給父級加display:inline-block;(這種情況當父級margin:0 auto;時不居中。隻有IE6,7居中)
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>給父級加display:inline-block</title>
<style>
.parentElement{ width:300px;margin:0 auto;border:10px solid #000; display:inline-block;}
.subElement{ width:200px;height:200px;background:red;float:left;}
</style>
</head>
<body>
<div class="parentElement">
<div class="subElement"></div>
</div>
</body>
</html>
3.在浮動元素下加
IE6下，塊元素有最小高度，即當height<19px時，預設為19px;
解決方法：font-size:0;或overflow:hidden;
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>在浮動元素下加<div class="clear"></div></title>
<style>
.parentElement{ width:300px;margin:0 auto;border:10px solid #000;}
.subElement{ width:200px;height:200px;background:red;float:left;}
.clear{ height:0px;font-size:0;clear:both;}
</style>
</head>
<body>
<div class="parentElement">
<div class="subElement"></div>
<div class="clear"></div>
</div>
</body>
</html>
4.在浮動元素下加
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>在浮動元素下加<br clear="all"/></title>
<style>
.parentElement{ width:300px;margin:0 auto;border:10px solid #000;}
.subElement{ width:200px;height:200px;background:red;float:left;}
</style>
</head>
<body>
<div class="parentElement">
<div class="subElement"></div>
<br clear="all"/>
</div>
</body>
</html>
5.給浮動元素父級加{zoom:1;}
:after{content:""; display:block;clear:both;}
在IE6，7下浮動元素的父級有寬度就不用清浮動
haslayout 根據元素内容的大小 或者父級的父級的大小來重新的計算元素的寬高
display: inline-block
height: (任何值除了auto)
float: (left 或 right)
width: (任何值除了auto)
zoom: (除 normal 外任意值)
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>無标題文檔</title>
<style>
.parentElement{margin:0 auto;border:10px solid #000;}
.subElement{ width:200px;height:200px;background:red;float:left;}
.clear{zoom:1;}
.clear:after{content:""; display:block;clear:both;}
</style>
</head>
<body>
<div class="parentElement clear">
<div class="subElement"></div>
</div>
</body>
</html>
6.給浮動元素父級加overflow:auto;或者overflow:hidden;
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>無标題文檔</title>
<style>
.parentElement{ width:300px;border:10px solid #000;overflow:hidden;}
.subElement{ width:200px;height:200px;background:Red;float:left;}
</style>
</head>
<body>
<div class="parentElement">
<div class="subElement"></div>
</div>
</body>
</html>
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