l元素浮动之后,能设置宽度的话就给元素加宽度.如果需要宽度是内容撑开,就给它里边的块元素加上浮动；
解决方案：给需要宽度由内容撑开的元素加上浮动
<! DOCTYPE html>
< html>
< head>
< meta charset= "utf-8" >
< title></title >
< style>
.box{width :400px ;border: 1px solid black;overflow: hidden;}
.left{float :left; background: red;}
.right{float :right; background: blue;}
h2{margin :0; height:30 px;float : left ;}
</ style>
</ head>
< body>
< div class= "box">
< div class= "left">
< h2>左边</h2>
</ div>
< div class= "right" >
< h2>右边</h2>
</ div>
</ div>
</ body>
</ html>
l第一块元素浮动,第二块元素加margin值等于第一块元素,在IE6下会有间隙问题;
解决方案：不建议这么写，用浮动解决
<! DOCTYPE html>
< html>
< head>
< meta charset= "utf-8" >
< title></title >
< style>
.box{width :500px ;}
.left{width :200px ;height: 200px; float:left ;background: red}
.right{width :200px ;height: 200px; background: blue; margin-left: 200px; }
</ style>
</ head>
< body>
< div class= "box">
< div class= "left"></div >
< div class= "right" ></div>
</ div>
</ body>
</ html>
lIE6下子元素超出父级宽高，会把父级的宽高撑开
解决方案：子元素高度不要超过父级高度
<! DOCTYPE html>
< html>
< head>
< meta charset= "utf-8" >
< title></title >
< style>
.box{
width: 200px;
height: 200px;
border: 1px solid red;
}
.item{
width: 100px;
height: 460px;
background-color: blue;
}
</ style>
</ head>
< body>
< div class= "box">
< div class= "item"></div >
</ div>
</ body>
</ html>
lp标签包含块元素嵌套规则。
解决方案：p标签不要嵌套块元素
<! DOCTYPE html>
< html>
< head>
< meta charset= "utf-8" >
< title></title >
</ head>
< body>
< p>
< div>div</div >
</ p>
</ body>
</ html>
lmargin兼容性问题
1、父子级包含的时候子级的margin-top会传递给父级
2、同级元素上下外边距会叠压；
解决方案:
问题1、触发haslayout、BFC。
问题2、尽量使用同一方向的margin，比如都设置top或者bottom；或者用padding代替.
<! DOCTYPE html>
< html>
< head>
< meta charset= "utf-8" >
< title></title >
< style>
.box{
background-color: green;
}
.head{
height: 30px;
background-color: red;
margin: 50px;
}
.content{
height: 30px;
background-color: blue;
margin: 50px;
}
</ style>
</ head>
< body>
< div class= "box">
< div class= "head">head</div >
< div class ="content">content</div >
</ div>
</ body>
</ html>
ldisplay:inline-block
解决方案：针对ie6、7使用hack添加display:inline和zoom:1
<! DOCTYPE html>
< html lang= "en">
< head>
< meta charset= "UTF-8" >
< title>inline-block</title>
< style type= "text/css" >
div{
width: 100px;
height: 100px;
display:inline-block ;
border:1 px solid red;
font-size: 12px;
*display: inline;
*zoom: 1;
}
span{
width: 100px;
height: 100px;
display:inline-block ;
border:1 px solid red;
font-size: 24px;
*display: inline;
*zoom: 1;
*margin-right: -4px ;
}
section{
font-size:0 ;
}
</style>
</ head>
< body>
< p>块元素转内联块</p>
< hr>
< section>
< div>块1</div>
< div>块2</div>
< div>块3</div>
</ section>
< p>内联元素转内联块</ p>
< hr>
< section>
< span href= "">内联1</span>
< span href= "">内联2</span>
< span href= "">内联3</span>
</ section>
</ body>
</ html>
lIE6 最小高度问题
解决方案：针对ie6、7使用hack添加overflow:hidden
<! DOCTYPE html>
< html>
< head>
< meta charset= "utf-8" >
< title></title >
< style>
.box{
height: 1px;
background-color: red;
overflow: hidden;
}
</ style>
</ head>
< body>
< div class= "box"></div >
</ body>
</ html>
lIE6 双边距
解决方案:针对ie6、7使用hack添加display:inline
<! doctype html>
< html lang= "en">
< head>
< meta charset= "UTF-8" />
< title></title >
< style>
body{margin :0}
.box{
width: 200px;
height: 200px;
margin: 100px;
background-color: red;
float: left;
*display: inline;
}
</ style>
</ head>
< body>
< div class= "box"></div >
</ body>
</ html>
lli里元素都浮动 li 在IE6 7 下方会产生4px间隙问题
解决方案：针对ie6、7使用hack添加vertical-align
<! DOCTYPE html>
< html>
< head>
< meta charset= "utf-8" >
< title></title >
< style>
.list{
margin: 0;
padding: 0;
list-style: none;
width: 300px;
}
.list li {
height: 30px;
border: 1px solid red;
line-height: 30px;
*vertical-align: top;
}
.list li a{
float: left;
}
.list li span{
float: right;
}
</ style>
</ head>
< body>
< ul class= "list">
< li>
< a href= "">左侧</a>
< span>右侧</span>
</ li>
< li>
< a href= "">左侧</a>
< span>右侧</span>
</ li>
</ ul>
</ body>
</ html>
l浮动元素之间注释，导致多复制一个文字问题
解决方案：两个浮动元素中间有注释或者内嵌元素并且和父级宽度相差不超过3像素，文字就被复制。所以避免注释和内联元素的出现。
<! doctype html>
< html>
< head>
< meta charset= "utf-8" >
< title>无标题文档</title>
< style>
.wrap {width: 400px; }
.left {float: left;}
.right {float: right;width :400px ;}
</ style>
</ head>
< body>
< div class= "wrap">
< div class= "left"></div >
< span></span ><span></ span><!-- IE下文字溢出BUG -->
< div class= "right" >↓这是多出来的一只猪</ div>
</ div>
</ body>
</ html>
lIE6 7 父级元素的overflow:hidden 是包不住子级的relative
解决方案：针对ie6、7使用hack给父级定位元素添加position:relative
<! DOCTYPE html>
< html>
< head>
< meta charset= "utf-8" >
< title></title >
< style>
*{
margin: 0;
padding: 0;
}
.box{
width: 200px;
height: 200px;
background-color: red;
border:4 px solid black;
overflow: hidden;
* position: relative;
}
.item{
width: 300px;
height: 300px;
background-color: blue;
position: relative;
}
</ style>
</ head>
< body>
< div class= "box">
< div class= "item"></div >
</ div>
</ body>
</ html>
lIE6下绝对定位元素父级宽高是奇数,绝对定位元素的right和bottom值会有1px的偏差
解决方案：避免父级宽高出现奇数
<! DOCTYPE html>
< html>
< head>
< meta charset= "utf-8" >
< title></title >
< style>
*{margin :0; padding:0 ;}
.box{
width: 308px;
height: 408px;
background-color: red;
position:absolute ;
}
.item{
width: 100px;
height: 100px;
background-color: green;
position: absolute;
right: 0;
bottom: 0;
}
</ style>
</ head>
< body>
< div class= "box">
< div class= "item"></div >
</ div>
</ body>
</ html>
lIE6下绝对定位元素和浮动元素并列绝对定位元素消失
解决方案：浮动元素和绝对定位元素是同级的话，定位元素会消失。所以只要不是同级就可以避免这个问题。
<! doctype html>
< html>
< head>
< meta charset= "utf-8" >
< title>无标题文档</title>
< style>
.box {width: 200px; height:200 px; border :1px solid #000; position :relative; }
.box div{ width:150 px;height :150px ; background :Red;margin-left :50px ; float :left; display:inline ;}
.box span{ width :50px ;height: 50px; background:yellow; position :absolute; top:-10 px;right :-20px ;}
</ style>
</ head>
< body>
< div class= "box">
< div></div >
< p><span ></span></ p>
</ div>
</ body>
</ html>
lIE6 下input的空隙 和 border问题
解决方案：给input浮动清除空隙；
<! doctype html>
< html>
< head>
< meta charset= "utf-8" >
< title>无标题文档</title>
< style>
.box {width: 200px; border:1 px solid #000 ; background: Red;}
.box input {border: none;margin :0; padding:0 ;width: 200px; height:30 px; background :#fff; float:left }
</ style>
</ head>
< body>
< div class= "box">
< input type= "text" />
</ div>
</ body>
</ html>
lIE6下输入类型表单控件背景问题
解决方案：设置background-attachment:fixed
<! DOCTYPE html>
< html>
< head>
< meta charset= "utf-8" >
< title></title >
< style>
input{
width: 200px;
height: 30px;
background: url(mail.jpg) no-repeat ;
background-attachment : fixed ;
}
</style>
</ head>
< body>
< input type= "text" />
</ body>
</ html>