bootstrap实战经验

凡是基本的布局需要float实现的,都可以考虑利用网格布局。

1,.jumbotron可以形成一个青灰色的背景,并自动调节对应边距

2,.panel的应用十分广泛,可以自动设置合适的padding.甚至利用它实现footer等(panel-footer)

3, text-justify对齐方式的使用

4,可以使用网格布局来控制图片的大小,结合max-width:100%.

5,top 和left是针对元素的左上角而言,absolute定位的占据一定面积的元素而言,针对于父元素的水平居中对齐,使用left:50%后,还需要margin:-水平宽度的一半。

6,外围元素设定clearfix之后,可以解决其中的浮动元素凸出的问题,可是如果外围元素浮动定位,内层元素决定定位造成的凸出,不能使用这种方法来解决,只能够定义外围元素的高度。

7,如果height,line-height比元素的默认高度还小,不可能得到垂直居中的效果。

8,元素一旦脱离页面流(float,绝对定位,相对定位),就相当于一个inline-block,可以为之设定宽度,为内连元素设置宽度没有效果。

9,为链接设置样式要遵循love hate的顺序(link,visited,hover,active)

10,bootstrap默认的样式可以被覆盖,例如,对于轮播组件,可以利用下列代码更改左右导航的样式。

11.创建响应式的布局,对于外层div的width,margin等,要善于利用百分比作为单位;同时限定max-width诸如:

 

.section{
    width:75%;
    max-width:600px;
    margin:5% auto 0;
    background-color:rgba(255,255,255,0.3);    
    padding:3%;
}
百分比响应式布局

 

 

.carousel-control.left, .carousel-control.right {
  top: 40%;
  background: none;
  font-size: 50px;
}
轮播导航样式覆盖

 12,善于使用rgba造成蒙版效果

13,bootstrap的col之间没有margin,但是内部有一定的padding。

14,利用transform,transion可以实现一些2d,乃至3d的旋转效果,一个示意可以参见:http://codepen.io/betdream/details/qiGrg

 

项目总结

一、<!--timeline--项目>

 1.如何实现带有箭头的div,利用:before,:after以及对应的border属性,其中,border-width以及偏移的设置是有规律而非随意的。

2,如何实现贯穿页面中间的竖线,利用before,top:0;bottom:0,width:50%来实现。

该项目值得好好琢磨,具体源代码如下:

<!doctype html>
<html lang="zh-hans">
<head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <link rel="stylesheet" href="lib/bootstrap/css/bootstrap.min.css">
    <link rel="stylesheet" href="css/timeline.css">
    <title>timeline布局</title>
</head>
<body>
<div>
    <div class="container">
        <div class="page-header">
            <h1>Timeline</h1>
        </div>
        <ul class="timeline">
            <li class="timeline-item left"> 
                <div class="timeline-badge info">
                    <span class="glyphicon glyphicon-check"></span>
                </div>
                <div class="timeline-panel">
                    <div class="timeline-title">
                        <h4>Mussum ipsum cacilds</h4>
                        <p class="text-muted"><small><span class="glyphicon glyphicon-time"></span> 11 hours ago via Twitter</small></p>
                    </div>
                    <div class="timeline-body">
                        <p>Mussum ipsum cacilds, vidis litro abertis. Consetis adipiscings elitis. Pra lá , depois divoltis porris, paradis. Paisis, filhis, espiritis santis. Mé faiz elementum girarzis, nisi eros vermeio, in elementis mé pra quem é amistosis quis leo. Manduma pindureta quium dia nois paga. Sapien in monti palavris qui num significa nadis i pareci latim. Interessantiss quisso pudia ce receita de bolis, mais bolis eu num gostis.</p>
                    </div>
                </div>
            </li>
            
            <li class="timeline-item right">
                <div class="timeline-badge primary">
                    <span class="glyphicon glyphicon-envelope"></span>
                </div>
                <div class="timeline-panel">
                    <div class="timeline-title">
                        <h4>Mussum ipsum cacilds</h4>
 
                    </div>
                    <div class="timeline-body">
                    <p>Mussum ipsum cacilds, vidis litro abertis. Consetis adipiscings elitis. Pra lá , depois divoltis porris, paradis. Paisis, filhis, espiritis santis. Mé faiz elementum girarzis, nisi eros vermeio, in elementis mé pra quem é amistosis quis leo. Manduma pindureta quium dia nois paga. Sapien in monti palavris qui num significa nadis i pareci latim. Interessantiss quisso pudia ce receita de bolis, mais bolis eu num gostis.
Suco de cevadiss, é um leite divinis, qui tem lupuliz, matis, aguis e fermentis. Interagi no mé, cursus quis, vehicula ac nisi. Aenean vel dui dui. Nullam leo erat, aliquet quis tempus a, posuere ut mi. Ut scelerisque neque et turpis posuere pulvinar pellentesque nibh ullamcorper. Pharetra in mattis molestie, volutpat elementum justo. Aenean ut ante turpis. Pellentesque laoreet mé vel lectus scelerisque interdum cursus velit auctor. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Etiam ac mauris lectus, non scelerisque augue. Aenean justo massa.</p>
                    </div>
                </div>
            </li>
            
            <li class="timeline-item left">
                <div class="timeline-badge sucess">
                    <span class="glyphicon glyphicon-user"></span>
                </div>
                <div class="timeline-panel">
                    <div class="timeline-title">
                        <h4>Mussum ipsum cacilds</h4>
                         
                    </div>
                    <div class="timeline-body">
                    <p>Mussum ipsum cacilds, vidis litro abertis. Consetis adipiscings elitis. Pra lá , depois divoltis porris, paradis. Paisis, filhis, espiritis santis. Mé faiz elementum girarzis, nisi eros vermeio, in elementis mé pra quem é amistosis quis leo. Manduma pindureta quium dia nois paga. Sapien in monti palavris qui num significa nadis i pareci latim. Interessantiss quisso pudia ce receita de bolis, mais bolis eu num gostis.</p>
                    </div>
                </div>
            </li>
            
            <li class="timeline-item right">
                <div class="timeline-panel">
                    <div class="timeline-title">
                        <h4>Mussum ipsum cacilds</h4>
                         
                    </div>
                    <div class="timeline-body">
                    <p>Mussum ipsum cacilds, vidis litro abertis. Consetis adipiscings elitis. Pra lá , depois divoltis porris, paradis. Paisis, filhis, espiritis santis. Mé faiz elementum girarzis, nisi eros vermeio, in elementis mé pra quem é amistosis quis leo. Manduma pindureta quium dia nois paga. Sapien in monti palavris qui num significa nadis i pareci latim. Interessantiss quisso pudia ce receita de bolis, mais bolis eu num gostis.</p>
                    </div>
                </div>
            </li>
            
            <li class="timeline-item left">
                <div class="timeline-badge danger">
                    <span class="glyphicon glyphicon-user"></span>
                </div>
                <div class="timeline-panel">
                    <div class="timeline-title">
                        <h4>Mussum ipsum cacilds</h4>
                         
                    </div>
                    <div class="timeline-body">
                    <p>Mussum ipsum cacilds, vidis litro abertis. Consetis adipiscings elitis. Pra lá , depois divoltis porris, paradis. Paisis, filhis, espiritis santis. Mé faiz elementum girarzis, nisi eros vermeio, in elementis mé pra quem é amistosis quis leo. Manduma pindureta quium dia nois paga. Sapien in monti palavris qui num significa nadis i pareci latim. Interessantiss quisso pudia ce receita de bolis, mais bolis eu num gostis.</p>
                    </div>
                    <div class="timeline-footer">
                        <button class="btn btn-primary"><span class="glyphicon glyphicon-cog"></span> <span class="caret"></span></button>
                    </div>
                </div>                
            </li>
            
            <li class="timeline-item left">
                <div class="timeline-panel ">
                    <div class="timeline-title">
                        <h4>Mussum ipsum cacilds</h4>
                         
                    </div>
                    <div class="timeline-body">
                    <p>Mussum ipsum cacilds, vidis litro abertis. Consetis adipiscings elitis. Pra lá , depois divoltis porris, paradis. Paisis, filhis, espiritis santis. Mé faiz elementum girarzis, nisi eros vermeio, in elementis mé pra quem é amistosis quis leo. Manduma pindureta quium dia nois paga. Sapien in monti palavris qui num significa nadis i pareci latim. Interessantiss quisso pudia ce receita de bolis, mais bolis eu num gostis.</p>
                    </div>
                </div>
            </li>
            
            <li class="timeline-item right">
                <div class="timeline-badge warning">
                    <span class="glyphicon glyphicon-user"></span>
                </div>
                <div class="timeline-panel">
                    <div class="timeline-title">
                        <h4>Mussum ipsum cacilds</h4>
                         
                    </div>
                    <div class="timeline-body">
                    <p>Mussum ipsum cacilds, vidis litro abertis. Consetis adipiscings elitis. Pra lá , depois divoltis porris, paradis. Paisis, filhis, espiritis santis. Mé faiz elementum girarzis, nisi eros vermeio, in elementis mé pra quem é amistosis quis leo. Manduma pindureta quium dia nois paga. Sapien in monti palavris qui num significa nadis i pareci latim. Interessantiss quisso pudia ce receita de bolis, mais bolis eu num gostis.</p>
                    </div>
                </div>                
            </li>
        <ul>
    </div>
</div>
</body>
</html>
timeline项目html代码
ul.timeline{
    list-style:none;
    /*
    border:1px solid #000;
    */
    padding:0;
    position:relative;
}
/*实现页面中间的竖线*/
ul.timeline:before{
    position:absolute;
    width:3px;
    height:auto;
    background:#eee;
    content:"";
    top:0;
    bottom:0;
    left:50%;
    margin-left:-1.5px;
}
.timeline > li{
    /*
    border:2px solid #345;
    */
    margin-bottom:15px;
    padding:20px;
    position:relative;
}    
.timeline >li>.timeline-badge{
    border-radius:50%;
    width:50px;
    height:50px;
    line-height:50px;
    position:absolute;
    top:28px;
    left:50%;
    margin-left:-25px;
    text-align:center;
    font-size:1.3em;
    color:#fff;
    background-color:#eee;
    z-index:1000;
}

.timeline > li > .timeline-panel{
    width:46%;
    border:2px solid #eee;
    box-shadow:0 3px 5px #eee;
    padding:20px;
    position:relative;
    text-align:justify;
}

.timeline > li.left>.timeline-panel{
    float:left;
}

.timeline > li.right>.timeline-panel{
    float:right;
}
.timeline > li:after{
    content:" ";
    display:table;
    clear:both;
}

/*实现带有左箭头的div*/
.timeline>li.left>.timeline-panel:before{
    content:"";
    border-left:18px solid #eee;    
    border-top:18px solid transparent;
    border-bottom:18px solid transparent;    
    position:absolute;
    top:12px;
    right:-18px;
    z-index:100;
}
.timeline>li.left>.timeline-panel:after{
    content:"";
    border-left:16px solid #fff;    
    border-top:16px solid transparent;
    border-bottom:16px solid transparent;    
    position:absolute;
    top:14px;
    right:-16px;
    z-index:100;
}


/*实现带有右箭头的div*/
.timeline>li.right>.timeline-panel:before{
    content:"";
    border-right:18px solid #eee;    
    border-top:18px solid transparent;
    border-bottom:18px solid transparent;    
    position:absolute;
    top:12px;
    left:-18px;
    z-index:100;
}
.timeline>li.right>.timeline-panel:after{
    content:"";
    border-right:16px solid #fff;    
    border-top:16px solid transparent;
    border-bottom:16px solid transparent;    
    position:absolute;
    top:14px;
    left:-16px;
    z-index:100;
}
.timeline>li .timeline-footer{
    padding-left:10px;
    padding-right:10px;
    border-top:1px solid #eee;
    padding-top:15px;
}

.timeline-badge.primary {
  background-color: #2e6da4 !important;
}
.timeline-badge.success {
  background-color: #3f903f !important;
}
.timeline-badge.warning {
  background-color: #f0ad4e !important;
}
.timeline-badge.danger {
  background-color: #d9534f !important;
}
.timeline-badge.info {
  background-color: #5bc0de !important;
}
timeline项目源代码

二、<!--网格布局和列表布局的转换>

  1.如何实现网格布局和列表布局的转换

  2,如何实现圆角、圆角间隔和hover的动态效果。

<!Doctype html>
<html>
<head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <link rel="stylesheet" href="lib/bootstrap/css/bootstrap.min.css">
    <link rel="stylesheet" href="css/myblog.css">
</head>
<body>
    <h1 class="banner text-center text-primary">My Blog</h1>
    <div class="container">
        <div class="switch btn-group pull-right">
            <button type="button" class="btn btn-primary"><span class="glyphicon glyphicon-th-large"></span></button>
            <button type="button" class="btn btn-primary"><span class="glyphicon glyphicon-th-list"></span></button>
        </div>
    </div>
    <div class="article_list container">
        <div class="row">
            <div class="article_wrapper col-xs-12">
                <a class="more_link" href="#">more</a>
                <div class="img_wrapper"><img src="img/blog/article1.jpg"/></div>
                <h2 class="article_title ">Lorem ipsum dolor</h2>
                <p class="article_content">Lorem ipsum dolor sit amet, consectetur adipisicing elit. Amet ducimus totam quasi nam porro sed.</p>
            </div>
            <div class="article_wrapper col-xs-12">
                <a class="more_link" href="#">more</a>
                <div class="img_wrapper"><img src="img/blog/article2.jpg"/></div>
                <h2 class="article_title ">Lorem ipsum dolor</h2>
                <p class="article_content">Lorem ipsum dolor sit amet, consectetur adipisicing elit. Amet ducimus totam quasi nam porro sed.</p>
            </div>
            <div class="article_wrapper col-xs-12">
                <a class="more_link" href="#">more</a>
                <div class="img_wrapper"><img src="img/blog/article3.jpg"/></div>
                <h2 class="article_title ">Lorem ipsum dolor</h2>
                <p class="article_content">Lorem ipsum dolor sit amet, consectetur adipisicing elit. Amet ducimus totam quasi nam porro sed.</p>
            </div>
            <div class="article_wrapper col-xs-12">
                <a class="more_link" href="#">more</a>
                <div class="img_wrapper"><img src="img/blog/article4.jpg"/></div>
                <h2 class="article_title ">Lorem ipsum dolor</h2>
                <p class="article_content">Lorem ipsum dolor sit amet, consectetur adipisicing elit. Amet ducimus totam quasi nam porro sed.</p>
            </div>
            <div class="article_wrapper col-xs-12">
                <a class="more_link" href="#">more</a>
                <div class="img_wrapper"><img src="img/blog/article5.jpg"/></div>
                <h2 class="article_title">Lorem ipsum dolor</h2>
                <p class="article_content">Lorem ipsum dolor sit amet, consectetur adipisicing elit. Amet ducimus totam quasi nam porro sed.</p>
            </div>
        </div>
    </div>
    

        
    <script src="lib/jquery-2.1.4.min.js"></script>
    <script src="lib/bootstrap/js/bootstrap.min.js"></script>
    <script src="js/myblog.js"></script>
</body>
</html>
布局切换html代码
body{
    background-color: #CDE;
}
.banner{
    font-family:"Times New Roman",Serif;
    font-size:46px;
    font-weight:bolder;
    padding-top:20px;
    padding-left:20px;
}
.switch{
    margin-bottom:10px;
}
 .article_wrapper{
    background-color:#fff;
    padding-left:175px;
    padding-right:75px;
    margin-bottom:30px;
    border-radius:100px;
    position:relative;
    height:150px;
    cursor:pointer;
    
 }
 
 .article_wrapper a{
    position:absolute;
    left:0;
    right:0;
    width:100%;
    height:150px;
    line-height:150px;
    text-align:center;
    font-weight:bolder;
    font-style:italic;
    font-size:40px;
    color:#428bca;
    opacity:0;
    text-decoration:none;
    background-color:#fff;
    border-radius:100px;
    
 }
 .article_wrapper:hover a{
    opacity:1;
 }
 
 .article_wrapper .img_wrapper{
    border-radius:100px;
    padding:10px;
    background-color:#CDE;
    position:absolute;
    left:-10px;
    top:-10px;
    padding:10px;
    height:170px;
    transition:all 0.2s;
 }
 .article_wrapper:hover .img_wrapper{
    padding:5px;
    transform:rotate(5deg);
 }
 
 .article_wrapper img{
    border-radius:100px;
    height:150px;
    transition:all 0.2s;
 }
 .article_wrapper:hover img{
    width:160px;
    height:160px;
 }

 .article_wrapper h2{
    font-size:20px;
    color: #428bca;
    border-bottom:2px solid #CDE;
    height:75px;
    line-height:75px;
    margin-top:0;
 }
 
.article_wrapper p{
    font-size:14px;
 }
 
 /*切换之后的布局*/
 .blog{
    padding-left:10px;
    padding-right:10px;
    border-radius:5px;    
    height:auto;
    /*修复图片的top造成的重叠*/
    margin-top:90px;
    /*防止图片挡住文字*/
    padding-top:85px;
    border-left: 10px solid #CDE;
}

 .blog a{
    position:absolute;
    top:0;
    left:0;
    height:100%;
    padding-top:40px;
    border-radius:5px;
    
 }
 
 
 .blog .img_wrapper{
    position:absolute;
    width:170px;
    top:-85px;
    left:50%;
    margin-left:-85px;
 }

 .blog h2{
    font-size:14px;
    height:37.5px;
    line-height:37.5px;
 }
 .blog p{
    font-size:12px;
    padding-bottom:10px;
 }
 
 
布局切换项目css代码

 

三、导航栏的实现

导航栏是本质上是链接列表,要实现水平导航栏的时候,有两种方案:

首先都要为a设置样式:display:block;

1)基于浮动的思想,令li左浮动,这种方法的优点是li之间不会存在空格,缺点是左浮动要想实现居中的效果需要借助于其他方法。

2)给li设置样式:display:inline-block。这种方法的优点是容易控制居中对齐(给ul设置样式text-align:center),缺点是li之间存在空格。

2.多级导航栏

2.1一级导航栏水平,二级导航栏竖直

此时,利用bootstrap的导航组件很容易实现

2.2一级导航栏水平,二级,三级...等多级导航栏竖直 

<!doctype html>
<html lang="zh-hans">
<head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <link rel="stylesheet" href="css/menu.css">
    <title>多级菜单</title>
</head>
<body>
    <div id="mainnav" class="menu">  
        <ul>  
            <li><a href="#">Link</a></li>  
            <li><a href="#">Link</a></li>  
            <li class="expand"><a href="#">Link</a>  
                <ul>  
                    <li><a href="#">Link</a></li>  
                    <li><a href="#">Link</a></li>  
                    <li class="expand"><a href="#">很长很长很长很长很长很长很长很长很长很长</a>  
                        <ul>  
                            <li><a href="#">Link</a></li>  
                            <li><a href="#">Link</a></li>  
                            <li class="expand"><a href="#">LinkLink</a>  
                                <ul>  
                                    <li class="expand"><a href="#">Link</a>  
                                        <ul>  
                                            <li><a href="#">Link</a></li>  
                                            <li><a href="#">Link</a></li>  
                                            <li><a href="#">Link</a></li>  
                                            <li><a href="#">Link</a></li>  
                                            <li><a href="#">Link</a></li>  
                                        </ul>  
                                    </li>  
                                    <li><a href="#">Link</a></li>  
                                    <li class="expand"><span>span 菜单项</span>  
                                        <ul>  
                                            <li><span>span 菜单项</span></li>  
                                            <li><a href="#">Link</a></li>  
                                            <li><a href="#">Link</a></li>  
                                            <li><a href="#">Link</a></li>  
                                            <li><a href="#">Link</a></li>  
                                        </ul>  
                                    </li>  
                                    <li><a href="#">Link</a></li>  
                                    <li><a href="#">Link</a></li>  
                                </ul>  
                            </li>  
                            <li><a href="#">Link</a></li>  
                            <li><a href="#">Link</a></li>  
                        </ul>  
                    </li>  
                    <li><a href="#">Link</a></li>  
                    <li><a href="#">Link</a></li>  
                </ul>  
            </li>  
            <li><a href="#">Link</a></li>  
            <li><a href="#">Link</a></li>  
        </ul>  
    </div>  
    <script src="lib/jquery-2.1.4.min.js"></script>
    <script src="lib/bootstrap/js/bootstrap.min.js"></script>
</body>
多级竖直导航html

 

.menu ul{
    margin:0;
    padding:0;
    list-style:none;
}

.menu a,.menu span{
    text-decoration:none;
    display:block;
    height:30px;
    line-height:30px;
    overflow:hidden;
}
.menu>ul>li{
    float:left;
    width:60px;
    overflow:visibility;
}
.menu>ul>li ul{
    display:none;
    width:160px;
    border:1px solid highlight;
}
.menu li:hover>ul{
    display:block;
}
.menu li:hover>a{
    background-color:highlight;
}
.menu>ul>li li{
    width:160px;
}
.menu>ul>li>ul>li ul{
    position:absolute;
    margin-left:155px;
    margin-top:-30px;
}
.menu>ul>li li.expand{
    padding-right:20px;
}
多级竖直导航css样式
<!DOCTYPE HTML>
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
    <title>纯 CSS 多级菜单</title>
    <style>
        .menu{}
        .menu ul,.menu li{margin:0; padding:0;list-style:none outside;}
        .menu>ul{overflow:auto; display:inline-block;}
        .menu a,.menu span{ cursor:default; height:30px; line-height:30px; padding:0 5px; display:block; text-overflow:ellipsis; overflow:hidden; text-decoration:none; color:MenuText;}
        .menu a:hover,.menu span:hover,.menu li:hover>a,.menu li:hover>span{color:HighlightText;}
        .menu li:hover{background-color:Highlight;}
        .menu li:hover>ul{display:block;}
        .menu>ul>li{float:left;}
        .menu>ul>li ul{display:none;float:left; background-color:#fff; border:1px solid Highlight; position:absolute;}
        .menu>ul>li li{padding-left:25px;margin:2px;background:transparent url(data:image/gif;base64,R0lGODlhEAAQAIAAAJmZmf///yH5BAAAAAAALAAAAAAQABAAAAIjhI9pwe2+nmRRIQrmjBrmYB1Y93Ak+IXVd6LtiIZwa5JqWAAAOw==) no-repeat 5px center; width:150px;}
        .menu>ul>li>ul>li ul{margin-left:140px; margin-top:-30px;}
        .menu li.expand>a,.menu li.expand>span{background:transparent url(data:image/png;base64,R0lGODlhAwAQAIABAAAAAP///yH5BAEAAAEALAAAAAADABAAAAIKjI8JBtv/wko0FQA7) no-repeat right center; padding-right:10px; margin-right:5px;}
        .menu>ul>li.expand>a,.menu>ul>li.expand>span{ background-image:url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAYAAAADCAYAAACwAX77AAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsMAAA7DAcdvqGQAAAAaSURBVBhXY2BgYPiPAwOFMSXBgjAA0wnmAwASVQv19UVKmwAAAABJRU5ErkJggg==);}
    </style>
</head>

<body>

    <div id="mainnav" class="menu">
        <ul>
            <li><a href="#">Link</a></li>
            <li><a href="#">Link</a></li>
            <li class="expand"><a href="#">Link</a>
                <ul>
                    <li><a href="#">Link</a></li>
                    <li><a href="#">Link</a></li>
                    <li class="expand"><a href="#">很长很长很长很长很长很长很长很长很长很长</a>
                        <ul>
                            <li><a href="#">Link</a></li>
                            <li><a href="#">Link</a></li>
                            <li class="expand"><a href="#">LinkLink</a>
                                <ul>
                                    <li class="expand"><a href="#">Link</a>
                                        <ul>
                                            <li><a href="#">Link</a></li>
                                            <li><a href="#">Link</a></li>
                                            <li><a href="#">Link</a></li>
                                            <li><a href="#">Link</a></li>
                                            <li><a href="#">Link</a></li>
                                        </ul>
                                    </li>
                                    <li><a href="#">Link</a></li>
                                    <li class="expand"><span>span 菜单项</span>
                                        <ul>
                                            <li><span>span 菜单项</span></li>
                                            <li><a href="#">Link</a></li>
                                            <li><a href="#">Link</a></li>
                                            <li><a href="#">Link</a></li>
                                            <li><a href="#">Link</a></li>
                                        </ul>
                                    </li>
                                    <li><a href="#">Link</a></li>
                                    <li><a href="#">Link</a></li>
                                </ul>
                            </li>
                            <li><a href="#">Link</a></li>
                            <li><a href="#">Link</a></li>
                        </ul>
                    </li>
                    <li><a href="#">Link</a></li>
                    <li><a href="#">Link</a></li>
                </ul>
            </li>
            <li><a href="#">Link</a></li>
            <li><a href="#">Link</a></li>
        </ul>
    </div>

</body>
</html>
多级竖直导航完整版

上述案例中值得注意的是两点:

 1)height:30px;line-height:30px;overflow:hidden可以控制,即使文本过长,依旧能保证样式正常

2)绝对定位元素的非绝对定位用法,一般来说,position:absolute通常的用法是设置在position非static的父元素中(否则就是相对于body),通过设置top,left,bottom,right来控制布局;在本例中,则是利用无定位值的margin属性,将其占据的原来位置让出,推离原位置。可以参见http://www.zhangxinxu.com/wordpress/2010/01/absolute%E7%BB%9D%E5%AF%B9%E5%AE%9A%E4%BD%8D%E7%9A%84%E9%9D%9E%E7%BB%9D%E5%AF%B9%E5%AE%9A%E4%BD%8D%E7%94%A8%E6%B3%95/(这篇博客有些结论是错误的,不过其思考的思路可以借鉴)

3)width:100%宽度的指定

(1)对于不存在其他关系的嵌套,width:100%是直接基于父元素(父元素为块状元素或者宽度指定)

(2)对于存在float的嵌套,结论(1)依旧成立(因为float没有脱离页面流嘛)

(3)对于子元素是position:absolute的嵌套,要是其外层的所有元素中都没有用position:relative/absolute/fixed,则width:100%是基于body,否则就是离基最近的一个position:relative/absolute/fixed的元素。(毕竟,position:absolute就是针对于最近一个非static定位的父元素进行定位的嘛)

(4)对于子元素是Postion:relative的嵌套,它是相对于其本来的位置进行定位,不管其父元素有没有设置特殊定位,其width:100%都是相对于距离它最近的父元素。

(5)fixed元素的width:100%始终相对于body进行定位。

 

 

 

 

 

 

 

 

posted @ 2015-05-21 09:18  bobo的学习笔记  阅读(698)  评论(0编辑  收藏  举报