我无法弄清楚如何使用bootstrap将Nav项目居中。我在这里研究过很多帖子，但我仍然无法弄明白。自从我用HTML和CSS（岁月）编程以来已经有一段时间了，所以我非常生疏。我希望我能很快掌握它，因为像这样的小事真的很烦我。我尝试了许多不同的东西，并试图遵循许多不同的简单教程，但我无法弄清楚我需要做什么。帮助！
CSS：
.nav {
margin-bottom: 20px;
margin-left: 0;
list-style: none;
text-align: center;
}
.nav > li > a {
display: block;
}
.nav > li > a:hover,
.nav > li > a:focus {
text-decoration: none;
background-color: #eeeeee;
}
.nav > li > a > img {
max-width: none;
}
.nav > .pull-right {
float: right;
}
.nav-header {
display: block;
padding: 3px 15px;
font-size: 11px;
font-weight: bold;
line-height: 20px;
color: #999999;
text-shadow: 0 1px 0 rgba(255, 255, 255, 0.5);
text-transform: uppercase;
}
.nav li + .nav-header {
margin-top: 9px;
}
.nav-list {
padding-right: 15px;
padding-left: 15px;
margin-bottom: 0;
}
.nav-list > li > a,
.nav-list .nav-header {
margin-right: -15px;
margin-left: -15px;
text-shadow: 0 1px 0 rgba(255, 255, 255, 0.5);
}
.nav-list > li > a {
padding: 3px 15px;
}
.nav-list > .active > a,
.nav-list > .active > a:hover,
.nav-list > .active > a:focus {
color: #ffffff;
text-shadow: 0 -1px 0 rgba(0, 0, 0, 0.2);
background-color: #0088cc;
}
.nav-list [class^="icon-"],
.nav-list [class*=" icon-"] {
margin-right: 2px;
}
.nav-list .divider {
*width: 100%;
height: 1px;
margin: 9px 1px;
*margin: -5px 0 5px;
overflow: hidden;
background-color: #e5e5e5;
border-bottom: 1px solid #ffffff;
}
.nav-tabs,
.nav-pills {
*zoom: 1;
}
.nav-tabs:before,
.nav-pills:before,
.nav-tabs:after,
.nav-pills:after {
display: table;
line-height: 0;
content: "";
}
.nav-tabs:after,
.nav-pills:after {
clear: both;
}
.nav-tabs > li,
.nav-pills > li {
float: left;
}
.nav-tabs > li > a,
.nav-pills > li > a {
padding-right: 12px;
padding-left: 12px;
margin-right: 2px;
line-height: 14px;
}
.nav-tabs {
border-bottom: 1px solid #ddd;
}
.nav-tabs > li {
margin-bottom: -1px;
}
.nav-tabs > li > a {
padding-top: 8px;
padding-bottom: 8px;
line-height: 20px;
border: 1px solid transparent;
-webkit-border-radius: 4px 4px 0 0;
-moz-border-radius: 4px 4px 0 0;
border-radius: 4px 4px 0 0;
}
.nav-tabs > li > a:hover,
.nav-tabs > li > a:focus {
border-color: #eeeeee #eeeeee #dddddd;
}
.nav-tabs > .active > a,
.nav-tabs > .active > a:hover,
.nav-tabs > .active > a:focus {
color: #555555;
cursor: default;
background-color: #ffffff;
border: 1px solid #ddd;
border-bottom-color: transparent;
}
.nav-pills > li > a {
padding-top: 8px;
padding-bottom: 8px;
margin-top: 2px;
margin-bottom: 2px;
-webkit-border-radius: 5px;
-moz-border-radius: 5px;
border-radius: 5px;
}
.nav-pills > .active > a,
.nav-pills > .active > a:hover,
.nav-pills > .active > a:focus {
color: #ffffff;
background-color: #0088cc;
}
.nav-stacked > li {
float: none;
}
.nav-stacked > li > a {
margin-right: 0;
}
.nav-tabs.nav-stacked {
border-bottom: 0;
}
.nav-tabs.nav-stacked > li > a {
border: 1px solid #ddd;
-webkit-border-radius: 0;
-moz-border-radius: 0;
border-radius: 0;
}
.nav-tabs.nav-stacked > li:first-child > a {
-webkit-border-top-right-radius: 4px;
border-top-right-radius: 4px;
-webkit-border-top-left-radius: 4px;
border-top-left-radius: 4px;
-moz-border-radius-topright: 4px;
-moz-border-radius-topleft: 4px;
}
.nav-tabs.nav-stacked > li:last-child > a {
-webkit-border-bottom-right-radius: 4px;
border-bottom-right-radius: 4px;
-webkit-border-bottom-left-radius: 4px;
border-bottom-left-radius: 4px;
-moz-border-radius-bottomright: 4px;
-moz-border-radius-bottomleft: 4px;
}
.nav-tabs.nav-stacked > li > a:hover,
.nav-tabs.nav-stacked > li > a:focus {
z-index: 2;
border-color: #ddd;
}
.nav-pills.nav-stacked > li > a {
margin-bottom: 3px;
}
.nav-pills.nav-stacked > li:last-child > a {
margin-bottom: 1px;
}
.nav-tabs .dropdown-menu {
-webkit-border-radius: 0 0 6px 6px;
-moz-border-radius: 0 0 6px 6px;
border-radius: 0 0 6px 6px;
}
.nav-pills .dropdown-menu {
-webkit-border-radius: 6px;
-moz-border-radius: 6px;
border-radius: 6px;
}
.nav .dropdown-toggle .caret {
margin-top: 6px;
border-top-color: #0088cc;
border-bottom-color: #0088cc;
}
.nav .dropdown-toggle:hover .caret,
.nav .dropdown-toggle:focus .caret {
border-top-color: #005580;
border-bottom-color: #005580;
}
/* move down carets for tabs */
.nav-tabs .dropdown-toggle .caret {
margin-top: 8px;
}
.nav .active .dropdown-toggle .caret {
border-top-color: #fff;
border-bottom-color: #fff;
}
.nav-tabs .active .dropdown-toggle .caret {
border-top-color: #555555;
border-bottom-color: #555555;
}
.nav > .dropdown.active > a:hover,
.nav > .dropdown.active > a:focus {
cursor: pointer;
}
.nav-tabs .open .dropdown-toggle,
.nav-pills .open .dropdown-toggle,
.nav > li.dropdown.open.active > a:hover,
.nav > li.dropdown.open.active > a:focus {
color: #ffffff;
background-color: #999999;
border-color: #999999;
}
.nav li.dropdown.open .caret,
.nav li.dropdown.open.active .caret,
.nav li.dropdown.open a:hover .caret,
.nav li.dropdown.open a:focus .caret {
border-top-color: #ffffff;
border-bottom-color: #ffffff;
opacity: 1;
filter: alpha(opacity=100);
}
HTML：
<div class="navbar-wrapper">
<!-- Wrap the .navbar in .container to center it within the absolutely positioned parent. -->
<div class="container">
<div class="navbar navbar-inverse">
<div class="navbar-inner">
<!-- Responsive Navbar Part 1: Button for triggering responsive navbar (not covered in tutorial). Include responsive CSS to utilize. -->
<button type="button" class="btn btn-navbar" data-toggle="collapse" data-target=".nav-collapse">
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
</button>
<img class="brand" source="assets/images/logo.jpg"></img>
<!-- Responsive Navbar Part 2: Place all navbar contents you want collapsed withing .navbar-collapse.collapse. -->
<div class="nav-collapse collapse">
<ul class="nav">
<li class="active"><a href="index.html">Home</a></li>
<li><a href="contact.html">Contact</a></li>
<!-- Read about Bootstrap dropdowns at http://twbs.github.com/bootstrap/javascript.html#dropdowns -->
<li class="dropdown">
<a href="#" class="dropdown-toggle" data-toggle="dropdown">Expos <b class="caret"></b></a>
<ul class="dropdown-menu">
<li class="nav-header">Texas Expositions</li>
<li><a href="#">Longview</a></li>
<li><a href="#">Houston</a></li>
<li><a href="#">Austin</a></li>
<li><a href="#">Midland</a></li>
<li class="divider"></li>
<li class="nav-header">Other Expositions</li>
<li><a href="#">Louisiana</a></li>
<li><a href="#">Oklahoma</a></li>
</ul>
</li>
</ul>
</div><!--/.nav-collapse -->
</div><!-- /.navbar-inner -->
</div><!-- /.navbar -->
</div> <!-- /.container -->
</div><!-- /.navbar-wrapper -->
编辑：在index.html页面的顶部找到这个CSS，我相信这是我将导航栏项目居中的地方？
/* CUSTOMIZE THE NAVBAR
-------------------------------------------------- */
/* Special class on .container surrounding .navbar, used for positioning it into place. */
.navbar-wrapper {
position: absolute;
top: 0;
left: 0;
right: 0;
z-index: 10;
margin-top: 20px;
margin-bottom: -90px; /* Negative margin to pull up carousel. 90px is roughly margins and height of navbar. */
}
.navbar-wrapper .navbar {
}
/* Remove border and change up box shadow for more contrast */
.navbar .navbar-inner {
border: 0;
-webkit-box-shadow: 0 2px 10px rgba(0,0,0,.25);
-moz-box-shadow: 0 2px 10px rgba(0,0,0,.25);
box-shadow: 0 2px 10px rgba(0,0,0,.25);
}
/* Downsize the brand/project name a bit */
.navbar .brand {
padding: 14px 20px 16px; /* Increase vertical padding to match navbar links */
font-size: 16px;
font-weight: bold;
text-shadow: 0 -1px 0 rgba(0,0,0,.5);
}
/* Navbar links: increase padding for taller navbar */
.navbar .nav > li > a {
padding: 15px 20px;
}
/* Offset the responsive button for proper vertical alignment */
.navbar .btn-navbar {
margin-top: 10px;
}
/* CUSTOMIZE THE CAROUSEL
-------------------------------------------------- */
/* Carousel base class */
.carousel {
margin-bottom: 60px;
}
.carousel .container {
position: relative;
z-index: 9;
}
.carousel-control {
height: 80px;
margin-top: 0;
font-size: 120px;
text-shadow: 0 1px 1px rgba(0,0,0,.4);
background-color: transparent;
border: 0;
z-index: 10;
}
.carousel .item {
height: 500px;
}
.carousel img {
position: absolute;
top: 0;
left: 0;
min-width: 100%;
height: 500px;
}
.carousel-caption {
background-color: transparent;
position: static;
max-width: 550px;
padding: 0 20px;
margin-top: 200px;
}
.carousel-caption h1,
.carousel-caption .lead {
margin: 0;
line-height: 1.25;
color: #fff;
text-shadow: 0 1px 1px rgba(0,0,0,.4);
}
.carousel-caption .btn {
margin-top: 10px;
}
/* MARKETING CONTENT
-------------------------------------------------- */
/* Center align the text within the three columns below the carousel */
.marketing .span4 {
text-align: center;
}
.marketing h2 {
font-weight: normal;
}
.marketing .span4 p {
margin-left: 10px;
margin-right: 10px;
}
/* Featurettes
------------------------- */
.featurette-divider {
margin: 80px 0; /* Space out the Bootstrap <hr> more */
}
.featurette {
padding-top: 120px; /* Vertically center images part 1: add padding above and below text. */
overflow: hidden; /* Vertically center images part 2: clear their floats. */
}
.featurette-image {
margin-top: -120px; /* Vertically center images part 3: negative margin up the image the same amount of the padding to center it. */
}
/* Give some space on the sides of the floated elements so text doesn't run right into it. */
.featurette-image.pull-left {
margin-right: 40px;
}
.featurette-image.pull-right {
margin-left: 40px;
}
/* Thin out the marketing headings */
.featurette-heading {
font-size: 50px;
font-weight: 300;
line-height: 1;
letter-spacing: -1px;
}
/* RESPONSIVE CSS
-------------------------------------------------- */
@media (max-width: 979px) {
.container.navbar-wrapper {
margin-bottom: 0;
width: auto;
}
.navbar-inner {
border-radius: 0;
margin: -20px 0;
}
.carousel .item {
height: 500px;
}
.carousel img {
width: auto;
height: 500px;
}
.featurette {
height: auto;
padding: 0;
}
.featurette-image.pull-left,
.featurette-image.pull-right {
display: block;
float: none;
max-width: 40%;
margin: 0 auto 20px;
}
}
@media (max-width: 767px) {
.navbar-inner {
margin: -20px;
}
.carousel {
margin-left: -20px;
margin-right: -20px;
}
.carousel .container {
}
.carousel .item {
height: 300px;
}
.carousel img {
height: 300px;
}
.carousel-caption {
width: 65%;
padding: 0 70px;
margin-top: 100px;
}
.carousel-caption h1 {
font-size: 30px;
}
.carousel-caption .lead,
.carousel-caption .btn {
font-size: 18px;
}
.marketing .span4 + .span4 {
margin-top: 40px;
}
.featurette-heading {
font-size: 30px;
}
.featurette .lead {
font-size: 18px;
line-height: 1.5;
}
}
</style>