如何居中下拉导航栏，并使其仍然响应？

Question

如何使下拉导航栏居中，并使其仍然响应？我已经尝试了我在这个网站和互联网上找到的几乎所有方法，但仍然无法解决我的问题，一种方法几乎解决了我的问题，但使我的导航栏没有响应

body {
    color: #ffffff;
    background-color: #000000;

}

h1 {
    color: white;
    font-family: "orator std";
    font-size: 44px;
    letter-spacing: 0px;
    line-height: 8px;
}

h2 {
    color: white;
    font-family: "orator std";
    font-size: 19px;
    letter-spacing: 0px;
    line-height: 1px;
}



h3 {
    color: white;
    font-family: "orator std";
    font-size: 14px;
    letter-spacing: 1px;
    margin-right: 100px;
    margin-left: 100px;
}


h4 {
    color: white;
    font-family: "orator std";
    font-size: 19px;
    letter-spacing: 0px;
    text-align: center;
}

h5 {
    color: white;
    font-family: "orator std";
    font-size: 19px;
    letter-spacing: 0px;
}



.thumbnail {

    color: white;
    background-color: #414141;
    border-color: rgb(44, 44, 44);

}

.thumbnail .caption {
  padding: 9px;
  color: white;
  margin-top: -14px;
 
}

.navbar-brand { 
    margin-top: 15px; 
    max-width: 30px; 
    padding: 0; 
    max-height: 30px;

}

.img-responsive {margin:0 auto;
 }

.btn {
    color: #ffffff;
    text-align: center;
}
.btn:active {

    color: red !important;
}

.btn:hover {
    color: #8E8E8E;
}

.navbar {
    border-radius: 0px;
    border-width: 0px;
    margin-top: 20%;
    font-family: "Orator Std";
    font-size: 18px;
    color: #ffffff;
    background-color: #000000;
    vertical-align: center;
    text-align: center;
    margin-top: 0%;
}




.navbar li a {
    color: #ffffff !important;
}

.navbar li a:hover {

    color: gray !important;
}

.navbar-inner, .navbar .btn-navbar {
    background: #ffffff
}

.navbar-inverse .navbar-nav>li>a {

    border-bottom: white !important;
    border-radius: 5px !important;

}


.dropdown-menu {

    color: #ffffff;
    background-color: #000000;

}

.dropdown-submenu {
    position: relative;


}


.dropdown-submenu > .dropdown-menu {
    top: 0;
    left: 100%;
    margin-top: -6px;
    margin-left: -1px;
    -webkit-border-radius: 0px;
    -moz-border-radius: 0px 6px 6px 6px;
    border-radius: 0px;


}
.dropdown-submenu:hover > .dropdown-menu {
    display: block;
}
.dropdown-submenu > a:after {
    display: block;
    content:" ";
    float: right;
    width: 0px;
    height: 0px;
    border-color: transparent;
    border-style: solid;
    border-width: 5px 0px 5px 5px;
    border-left-color: #cccccc;
    margin-top: 5px;
    margin-right: -5px;

}
.dropdown-submenu:hover > a:after {
    border-left-color: #ffffff;

}
.dropdown-submenu.pull-left {
    float: none;
}
.dropdown-submenu.pull-left > .dropdown-menu {
    left: -100%;
    margin-left: 10px;
    -webkit-border-radius: 6px 0px 6px 6px;
    -moz-border-radius: 6px 0px 6px 6px;
    border-radius: 6px 0px 6px 6px;
}
@media screen and (max-width: 768px) {
    .navbar .navbar-collapse a {
        text-align: left;
        padding-left: 43%;
    }
    .dropdown-submenu a {
        padding-left: 44%;
    }
    .navbar .navbar-collapse .dropdown .dropdown-menu a {
        padding-left: 45%;
    }
}


#the-slider img{

  width: 100%;
  padding-left: 10%;
  padding-right: 10%;
  padding-top: 10%;
}


.navbar-nav li{
    position: relative
}

.navbar-nav li:not(:last-child):after{
    content: '';
    position: absolute;
    right: 0px;
    width: 1px;
    height: 50%;
    top: 20%;
    background: white;
}

.dropdown-menu li:not(:last-child):after{
    content: '';
    position: absolute;
    right: 0px;
    width: 0px;
    height: 50%;
    top: 20%;
    background: red;
}

<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css" rel="stylesheet">
    <link href="css/custom.css" rel="stylesheet">
    
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
    <script src="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.1/js/bootstrap.min.js"></script>
    
 

</head>

<body>

<nav role="navigation" class="navbar navbar-inverse"> <!-- start navigation button -->
    <!-- Brand and toggle get grouped for better mobile display -->
    <div class="navbar-header">
        <button type="button" data-target="#navbarCollapse" data-toggle="collapse" class="navbar-toggle"> <span class="sr-only">Toggle navigation</span>
 <span class="icon-bar"></span>
 <span class="icon-bar"></span>
 <span class="icon-bar"></span>

        </button> 

            
        <a href="index.html" class="pull-left"><img src="images/logonav1.png"></a>

    </div>
    <!-- Collection of nav links, forms, and other content for toggling -->

    <div id="navbarCollapse" class="collapse navbar-collapse">
        <ul class="nav navbar-nav navbar-center">
            <li class="#"><a href="#"><B><I>Home</B></I></a>

            </li>
            
            <li class="dropdown"> <a data-toggle="dropdown" class="dropdown-toggle" href="#"><B><I>Collection </B></I><b class="caret"></b></a>

                <ul role="menu" class="dropdown-menu">





                    <li><a href="#"><i class="fa fa-envelope-o fa-fw"></i><B><I>All Collection Portfolio</B></I></a>

                    

                    </li>
                    <li class="divider"></li>
                    <li><a href="#"><i class="fa fa-trash-o fa-fw"></i>Collection 1</a>
                    
                    </li>
                    <li><a href="collection2.html"><i class="fa fa-pencil-square-o fa-fw"></i>Collection 2</a>

                    </li>
                    <li><a href="#"><i class="fa fa-paper-plane-o  fa-fw"></i>Collection 3</a>






                    </li>
                    <li class="divider"></li>
                    <li><a href="#"><i class="fa fa-trash-o fa-fw"></i>Cita Tenun Indonesia</a>

                    </li>

                </ul>
            </li>
            
            <li class="dropdown"> <a data-toggle="dropdown" class="dropdown-toggle" href="#">Things <b class="caret"></b></a>

                <ul role="menu" class="dropdown-menu">
                    <li><a href="#"><i class="fa fa-envelope-o fa-fw"></i> Inbox</a>

                    </li>
                    <li><a href="#"><i class="fa fa-pencil-square-o  fa-fw"></i> Drafts</a>

                    </li>
                    <li><a href="#"><i class="fa fa-paper-plane-o  fa-fw"></i> Sent Items</a>

                    </li>
                    <li class="divider"></li>
                    <li><a href="#"><i class="fa fa-trash-o fa-fw"></i> Trash</a>

                        <li class="dropdown-submenu"> <a tabindex="-1" href="#"><i class="fa fa-hand-o-right fa-fw"></i> Profile</a>

                            <ul class="dropdown-menu">
                                <li><a href="#"><i class="fa fa-calendar-o fa-fw"></i> Account</a>

                                </li>
                                <li><a href="#"><i class="fa fa-folder-open-o  fa-fw"></i> Users</a>

                                </li>
                                <li><a href="#"><i class="fa fa-file-o fa-fw"></i> Login</a>

                                </li>
                            </ul>
                        </li>
                    </li>
                </ul>


            <li><a href="#">About</a>
            

            </li>
            <li><a href="#">Contact us</a>
            </li>
            </li>
        </ul>
        
        </ul>
    </div>
</nav> <!-- end navigation button-->




<!-- javascript -->
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
    <script src="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.1/js/bootstrap.min.js"></script>

</body>

Answer 1

问题是 Boostrap 将 navbar-nav 和 navbar-nav li 元素设置为 float: left;，因此它强制两者左对齐。

您需要通过在这些选择器上将 float 属性设置为 none !important 来覆盖 min-width: 768px 媒体查询的 Bootstrap 样式，并将 display: inline-block !important; 添加到 navbar-nav 元素。

您需要使用媒体查询才能应用更改仅当视口为 768 像素或更大时。

您需要添加到样式表的 CSS 规则应如下所示：

@media (min-width: 768px) {
  .navbar-nav > li {
    float: none !important;
    display: inline-block !important;
  }
  .navbar-nav {
    float: none !important;
  }
}

并应用于HTML：

body {
  color: #ffffff;
  background-color: #000000;
}
h1 {
  color: white;
  font-family: "orator std";
  font-size: 44px;
  letter-spacing: 0px;
  line-height: 8px;
}
h2 {
  color: white;
  font-family: "orator std";
  font-size: 19px;
  letter-spacing: 0px;
  line-height: 1px;
}
h3 {
  color: white;
  font-family: "orator std";
  font-size: 14px;
  letter-spacing: 1px;
  margin-right: 100px;
  margin-left: 100px;
}
h4 {
  color: white;
  font-family: "orator std";
  font-size: 19px;
  letter-spacing: 0px;
  text-align: center;
}
h5 {
  color: white;
  font-family: "orator std";
  font-size: 19px;
  letter-spacing: 0px;
}
.thumbnail {
  color: white;
  background-color: #414141;
  border-color: rgb(44, 44, 44);
}
.thumbnail .caption {
  padding: 9px;
  color: white;
  margin-top: -14px;
}
.navbar-brand {
  margin-top: 15px;
  max-width: 30px;
  padding: 0;
  max-height: 30px;
}
.img-responsive {
  margin: 0 auto;
}
.btn {
  color: #ffffff;
  text-align: center;
}
.btn:active {
  color: red !important;
}
.btn:hover {
  color: #8E8E8E;
}
.navbar {
  border-radius: 0px;
  border-width: 0px;
  margin-top: 20%;
  font-family: "Orator Std";
  font-size: 18px;
  color: #ffffff;
  background-color: #000000;
  vertical-align: center;
  text-align: center;
  margin-top: 0%;
}
.navbar li a {
  color: #ffffff !important;
}
.navbar li a:hover {
  color: gray !important;
}
.navbar-inner,
.navbar .btn-navbar {
  background: #ffffff
}
.navbar-inverse .navbar-nav>li>a {
  border-bottom: white !important;
  border-radius: 5px !important;
}
.dropdown-menu {
  color: #ffffff;
  background-color: #000000;
}
.dropdown-submenu {
  position: relative;
}
.dropdown-submenu > .dropdown-menu {
  top: 0;
  left: 100%;
  margin-top: -6px;
  margin-left: -1px;
  -webkit-border-radius: 0px;
  -moz-border-radius: 0px 6px 6px 6px;
  border-radius: 0px;
}
.dropdown-submenu:hover > .dropdown-menu {
  display: block;
}
.dropdown-submenu > a:after {
  display: block;
  content: " ";
  float: right;
  width: 0px;
  height: 0px;
  border-color: transparent;
  border-style: solid;
  border-width: 5px 0px 5px 5px;
  border-left-color: #cccccc;
  margin-top: 5px;
  margin-right: -5px;
}
.dropdown-submenu:hover > a:after {
  border-left-color: #ffffff;
}
.dropdown-submenu.pull-left {
  float: none;
}
.dropdown-submenu.pull-left > .dropdown-menu {
  left: -100%;
  margin-left: 10px;
  -webkit-border-radius: 6px 0px 6px 6px;
  -moz-border-radius: 6px 0px 6px 6px;
  border-radius: 6px 0px 6px 6px;
}
@media screen and (max-width: 768px) {
  .navbar .navbar-collapse a {
    text-align: left;
    padding-left: 43%;
  }
  .dropdown-submenu a {
    padding-left: 44%;
  }
  .navbar .navbar-collapse .dropdown .dropdown-menu a {
    padding-left: 45%;
  }
}
#the-slider img {
  width: 100%;
  padding-left: 10%;
  padding-right: 10%;
  padding-top: 10%;
}
.navbar-nav li {
  position: relative
}
.navbar-nav li:not(:last-child):after {
  content: '';
  position: absolute;
  right: 0px;
  width: 1px;
  height: 50%;
  top: 20%;
  background: white;
}
.dropdown-menu li:not(:last-child):after {
  content: '';
  position: absolute;
  right: 0px;
  width: 0px;
  height: 50%;
  top: 20%;
  background: red;
}
@media (min-width: 768px) {
  .navbar-nav > li {
    float: none !important;
    display: inline-block !important;
  }
  .navbar-nav {
    float: none !important;
  }
}

<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css" rel="stylesheet">
<link href="css/custom.css" rel="stylesheet">

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.1/js/bootstrap.min.js"></script>



</head>

<body>

  <nav role="navigation" class="navbar navbar-inverse">
    <!-- start navigation button -->
    <!-- Brand and toggle get grouped for better mobile display -->
    <div class="navbar-header">
      <button type="button" data-target="#navbarCollapse" data-toggle="collapse" class="navbar-toggle"> <span class="sr-only">Toggle navigation</span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>

      </button>


      <a href="index.html" class="pull-left">
        <img src="images/logonav1.png">
      </a>

    </div>
    <!-- Collection of nav links, forms, and other content for toggling -->

    <div id="navbarCollapse" class="collapse navbar-collapse">
      <ul class="nav navbar-nav navbar-center">
        <li class="#"><a href="#"><B><I>Home</B></I></a>

        </li>

        <li class="dropdown"> <a data-toggle="dropdown" class="dropdown-toggle" href="#"><B><I>Collection </B></I><b class="caret"></b></a>

          <ul role="menu" class="dropdown-menu">





            <li><a href="#"><i class="fa fa-envelope-o fa-fw"></i><B><I>All Collection Portfolio</B></I></a>



            </li>
            <li class="divider"></li>
            <li><a href="#"><i class="fa fa-trash-o fa-fw"></i>Collection 1</a>

            </li>
            <li><a href="collection2.html"><i class="fa fa-pencil-square-o fa-fw"></i>Collection 2</a>

            </li>
            <li><a href="#"><i class="fa fa-paper-plane-o  fa-fw"></i>Collection 3</a>






            </li>
            <li class="divider"></li>
            <li><a href="#"><i class="fa fa-trash-o fa-fw"></i>Cita Tenun Indonesia</a>

            </li>

          </ul>
        </li>

        <li class="dropdown"> <a data-toggle="dropdown" class="dropdown-toggle" href="#">Things <b class="caret"></b></a>

          <ul role="menu" class="dropdown-menu">
            <li><a href="#"><i class="fa fa-envelope-o fa-fw"></i> Inbox</a>

            </li>
            <li><a href="#"><i class="fa fa-pencil-square-o  fa-fw"></i> Drafts</a>

            </li>
            <li><a href="#"><i class="fa fa-paper-plane-o  fa-fw"></i> Sent Items</a>

            </li>
            <li class="divider"></li>
            <li><a href="#"><i class="fa fa-trash-o fa-fw"></i> Trash</a>

              <li class="dropdown-submenu"> <a tabindex="-1" href="#"><i class="fa fa-hand-o-right fa-fw"></i> Profile</a>

                <ul class="dropdown-menu">
                  <li><a href="#"><i class="fa fa-calendar-o fa-fw"></i> Account</a>

                  </li>
                  <li><a href="#"><i class="fa fa-folder-open-o  fa-fw"></i> Users</a>

                  </li>
                  <li><a href="#"><i class="fa fa-file-o fa-fw"></i> Login</a>

                  </li>
                </ul>
              </li>
            </li>
          </ul>


          <li><a href="#">About</a>


          </li>
          <li><a href="#">Contact us</a>
          </li>
        </li>
      </ul>

      </ul>
    </div>
  </nav>
  <!-- end navigation button-->




  <!-- javascript -->
  <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
  <script src="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.1/js/bootstrap.min.js"></script>

</body>

如何居中下拉导航栏，并使其仍然响应？

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