Bootstrap固定導航欄，帶縮放徽標，位於導航欄上方

Question

如何使用具有自舉的父徽標的固定導航欄。 當您滾動時，徽標會減少，但在固定導航欄中保持可見。

例如，對於萎縮的標誌和導航欄：https://doemee.zoetermeer.nl

Answer 1

您可以通過使用在nav引導類navbar-fixed-top並加入少許jQuery觸發window滾動事件實現這一目標。當您向下滾動或向上滾動時，只需切換CSS類即可。

演示：See here

$(document).ready(function() { 
 
     $(window).scroll(function() { 
 

 
      //Method 1: Using addClass and removeClass 
 
      //if ($(document).scrollTop() > 50) { 
 
      // $('.navbar-default').addClass('navbar-shrink'); 
 
      //} else { 
 
      // $('.navbar-default').removeClass('navbar-shrink'); 
 
      //} 
 

 
      //Method 2: Using toggleClass 
 
      $(".navbar-default").toggleClass("navbar-shrink", $(this).scrollTop() > 50) 
 
     }); 
 
    });

@media screen and (min-width: 992px) { 
 

 
     .navbar-default { 
 
      padding: 30px 0; 
 
      transition: padding 0.3s; 
 
     } 
 

 
      .navbar-default.navbar-shrink { 
 
       padding: 10px 0; 
 
      } 
 
    } 
 

 
    .navbar-default a { 
 
     color: #4D4D4D; 
 
     font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif; 
 
     text-transform: uppercase; 
 
     text-decoration: none; 
 
     line-height: 42px; 
 
     font-weight: 700; 
 
     font-size: 20px; 
 
    } 
 

 
    .navbar-default a.brand > img {    
 
     max-width: 70px; 
 
    } 
 

 
     .navbar-default a.active { 
 
      color: #2dbccb; 
 
     } 
 

 

 
    .content { 
 
     position: absolute; 
 
     width: 100%; 
 
     height: 100%; 
 
    } 
 

 
     .content > section { 
 
      width: 100%; 
 
      height: 100%; 
 
     } 
 

 
    #portfolio { 
 
     background: #2dbccb; 
 
    } 
 

 
    #about { 
 
     background-color: #eb7e7f; 
 
    } 
 

 
    #contact { 
 
     background-color: #415c71; 
 
    }

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> 
 

 
<!-- Navigation --> 
 
    <nav class="navbar navbar-default navbar-fixed-top"> 
 
     <div class="container"> 
 
      <!-- Brand and toggle get grouped for better mobile display --> 
 
      <div class="navbar-header page-scroll"> 
 
       <button type="button" class="navbar-toggle" data-toggle="collapse" data-target="#top-nav"> 
 
        <span class="sr-only">Toggle navigation</span> 
 
        <span class="icon-bar"></span> 
 
        <span class="icon-bar"></span> 
 
        <span class="icon-bar"></span> 
 
       </button> 
 
       <a class="brand" href="http://trungk18.github.io/"><img src="trungk18.png" class="img-responsive" title="trungk18" /></a> 
 
      </div> 
 
      <!-- Collect the nav links, forms, and other content for toggling --> 
 
      <div class="collapse navbar-collapse" id="top-nav"> 
 
       <ul class="nav navbar-nav navbar-right"> 
 
        <li class="page-scroll"> 
 
         <a href="#portfolio">Portfolio</a> 
 
        </li> 
 
        <li class="page-scroll"> 
 
         <a href="#about">About</a> 
 
        </li> 
 
        <li class="page-scroll"> 
 
         <a href="#contact">Contact</a> 
 
        </li> 
 
       </ul> 
 
      </div> 
 
      <!-- /.navbar-collapse --> 
 
     </div> 
 
     <!-- /.container-fluid --> 
 
    </nav> 
 

 
    <!-- Content Section --> 
 
    <div class="content"> 
 
     <section id="portfolio"></section> 
 
     <section id="about"></section> 
 
     <section id="contact"></section> 
 
    </div>