如何使我的固定＆＃34;移动导航＆＃34;当我向下滚动页面时出现栏？

Question

＆＃13;

＆＃13;

#web-nav {
  display: none;
}
#mobile-nav {
  width: 100%;
  background: url(img/menu-bg.png) repeat;
  height: 70px;
  display: block;
  position: fixed;
  z-index: 50;
  top: 0px;
}

＆＃13;

<nav id="mobile-nav">
  <a href="index.html">
    <img class="logo" src="admin/wp-content/themes/mame/assets/img/sicklehammer.png" />
  </a>
  <img class="drop-nav" src="open.png" />
</nav>
<nav id="mobile-expand">
  <img class="logo" src="logo.png" />
  <img class="close" src="img/close.png" />
  <div id="hidden-nav">

  </div>

  <ul id="menu">

    <li><a href="index.html">Home</a>
    </li>
    <li><a href="work/index.html">Work</a>
    </li>
    <li><a href="about/index.html">About</a>
    </li>
    <li><a href="blog/index.html">Blog</a>
    </li>
    <li><a href="contact/index.html">Contact</a>
    </li>
    <ul class="work-subs">

      <li><a href="/index.html">Movies</a>
      </li>
      <li><a href="/index.html">Photos</a>
      </li>
    </ul>
  </ul>
</nav>

＆＃13;

＆＃13;

＆＃13;

Answer 1

这就是我使用的 <script> $('#main-nav').hide(); $(window).scroll(function () { if ($(this).scrollTop() > 750) { $('#main-nav').fadeIn(); } else { $('#main-nav').fadeOut(); } });