Question

你有任何帮助，我在网上搜索并问一个比我更了解CSS的朋友，没有任何效果。我只是希望菜单在页面上居中而不是向左推。

HTML

<div id='cssmenu'>
<ul>
   <li class='active'><a href='index.html'><span>Home</span></a></li>
   <li class='has-sub'><a href='#'><span>Products</span></a>
      <ul>
         <li class='has-sub'><a href='#'><span>Product 1</span></a>
            <ul>
               <li><a href='#'><span>Sub Item</span></a></li>
               <li class='last'><a href='#'><span>Sub Item</span></a></li>
            </ul>
         </li>
         <li class='has-sub'><a href='#'><span>Product 2</span></a>
            <ul>
               <li><a href='#'><span>Sub Item</span></a></li>
               <li class='last'><a href='#'><span>Sub Item</span></a></li>
            </ul>
         </li>
      </ul>
   </li>
   <li><a href='#'><span>About</span></a></li>
   <li class='last'><a href='#'><span>Contact</span></a></li>
</ul>
</div>

CSS

#cssmenu {
  position: relative;
  height: 44px;
  background: #2b2f3a;
  width: auto;
}
#cssmenu ul {
  list-style: none;
  padding: 0;
  margin: 0;
  line-height: 1;
}
#cssmenu > ul {
  position: relative;
  display: block;
  background: #2b2f3a;
  height: 32px;
  width: 100%;
  z-index: 500;
}
#cssmenu > ul > li {
  display: block;
  position: relative;
  float: left;
  margin: 0;
  padding: 0;
}
#cssmenu > ul > #menu-button {
  display: none;
}
#cssmenu ul li a {
  display: block;
  font-family: Helvetica, sans-serif;
  text-decoration: none;
}
#cssmenu > ul > li > a {
  font-size: 14px;
  font-weight: bold;
  padding: 15px 20px;
  color: #7a8189;
  text-transform: uppercase;
  -webkit-transition: color 0.25s ease-out;
  -moz-transition: color 0.25s ease-out;
  -ms-transition: color 0.25s ease-out;
  -o-transition: color 0.25s ease-out;
  transition: color 0.25s ease-out;
}
#cssmenu > ul > li.has-sub > a {
  padding-right: 32px;
}
#cssmenu > ul > li:hover > a {
  color: #ffffff;
}
#cssmenu li.has-sub::after {
  display: block;
  content: '';
  position: absolute;
  width: 0;
  height: 0;
}
#cssmenu > ul > li.has-sub::after {
  right: 10px;
  top: 20px;
  border: 5px solid transparent;
  border-top-color: #7a8189;
}
#cssmenu > ul > li:hover::after {
  border-top-color: #ffffff;
}
#indicatorContainer {
  position: absolute;
  height: 12px;
  width: 100%;
  bottom: 0px;
  overflow: hidden;
  z-index: -1;
}
#pIndicator {
  position: absolute;
  height: 0;
  width: 100%;
  border: 12px solid transparent;
  border-top-color: #2b2f3a;
  z-index: -2;
  -webkit-transition: left .25s ease;
  -moz-transition: left .25s ease;
  -ms-transition: left .25s ease;
  -o-transition: left .25s ease;
  transition: left .25s ease;
}
#cIndicator {
  position: absolute;
  height: 0;
  width: 100%;
  border: 12px solid transparent;
  border-top-color: #2b2f3a;
  top: -12px;
  right: 100%;
  z-index: -2;
}
#cssmenu ul ul {
  position: absolute;
  left: -9999px;
  top: 70px;
  opacity: 0;
  -webkit-transition: opacity .3s ease, top .25s ease;
  -moz-transition: opacity .3s ease, top .25s ease;
  -ms-transition: opacity .3s ease, top .25s ease;
  -o-transition: opacity .3s ease, top .25s ease;
  transition: opacity .3s ease, top .25s ease;
  z-index: 1000;
}
#cssmenu ul ul ul {
  top: 37px;
  padding-left: 5px;
}
#cssmenu ul ul li {
  position: relative;
}
#cssmenu > ul > li:hover > ul {
  left: auto;
  top: 44px;
  opacity: 1;
}
#cssmenu ul ul li:hover > ul {
  left: 170px;
  top: 0;
  opacity: 1;
}
#cssmenu ul ul li a {
  width: 130px;
  border-bottom: 1px solid #eee;
  padding: 10px 20px;
  font-size: 12px;
  color: #9ea2a5;
  background: #fff;
  -webkit-transition: all .35s ease;
  -moz-transition: all .35s ease;
  -ms-transition: all .35s ease;
  -o-transition: all .35s ease;
  transition: all .35s ease;
}
#cssmenu ul ul li:hover > a {
  background: #f6f6f6;
  color: #8c9195;
}
#cssmenu ul ul li:last-child > a,
#cssmenu ul ul li.last > a {
  border-bottom: 0;
}
.submenuArrow {
  border: 6px solid transparent;
  width: 0;
  height: 0;
  border-bottom-color: #fff;
  position: absolute;
  top: -12px;
}
#cssmenu ul ul li.has-sub::after {
  border: 4px solid transparent;
  border-left-color: #9ea2a5;
  right: 10px;
  top: 12px;
  -moz-transition: all .2s ease;
  -ms-transition: all .2s ease;
  -o-transition: all .2s ease;
  transition: all .2s ease;
  -webkit-transition: -webkit-transform 0.2s ease, right 0.2s ease;
}
#cssmenu ul ul li.has-sub:hover::after {
  border-left-color: #fff;
  right: -5px;
  -webkit-transform: rotateY(180deg);
  -ms-transform: rotateY(180deg);
  -moz-transform: rotateY(180deg);
  -o-transform: rotateY(180deg);
  transform: rotateY(180deg);
}
@media all and (max-width: 800px), only screen and (-webkit-min-device-pixel-ratio: 2) and (max-width: 1024px), only screen and (min--moz-device-pixel-ratio: 2) and (max-width: 1024px), only screen and (-o-min-device-pixel-ratio: 2/1) and (max-width: 1024px), only screen and (min-device-pixel-ratio: 2) and (max-width: 1024px), only screen and (min-resolution: 192dpi) and (max-width: 1024px), only screen and (min-resolution: 2dppx) and (max-width: 1024px) {
  #cssmenu {
    width: auto;
  }
  #cssmenu ul {
    width: auto;
  }
  #cssmenu .submenuArrow,
  #cssmenu #indicatorContainer {
    display: none;
  }
  #cssmenu > ul {
    height: auto;
    display: block;
  }
  #cssmenu > ul > li {
    float: none;
  }
  #cssmenu li,
  #cssmenu > ul > li {
    display: none;
  }
  #cssmenu ul ul,
  #cssmenu ul ul ul,
  #cssmenu ul > li:hover > ul,
  #cssmenu ul ul > li:hover > ul {
    position: relative;
    left: auto;
    top: auto;
    opacity: 1;
    padding-left: 0;
  }
  #cssmenu ul .has-sub::after {
    display: none;
  }
  #cssmenu ul li a {
    padding: 12px 20px;
  }
  #cssmenu ul ul li a {
    border: 0;
    background: none;
    width: auto;
    padding: 8px 35px;
  }
  #cssmenu ul ul li:hover > a {
    background: none;
    color: #8c9195;
  }
  #cssmenu ul ul ul a {
    padding: 8px 50px;
  }
  #cssmenu ul ul ul ul a {
    padding: 8px 65px;
  }
  #cssmenu ul ul ul ul ul a {
    padding: 8px 80px;
  }
  #cssmenu ul ul ul ul ul ul a {
    padding: 8px 95px;
  }
  #cssmenu > ul > #menu-button {
    display: block;
    cursor: pointer;
  }
  #cssmenu #menu-button > a {
    padding: 14px 20px;
  }
  #cssmenu ul.open li,
  #cssmenu > ul.open > li {
    display: block;
  }
  #cssmenu > ul.open > li#menu-button > a {
    color: #fff;
    border-bottom: 1px solid rgba(150, 150, 150, 0.1);
  }
  #cssmenu #menu-button::after {
    display: block;
    content: '';
    position: absolute;
    height: 3px;
    width: 22px;
    border-top: 2px solid #7a8189;
    border-bottom: 2px solid #7a8189;
    right: 20px;
    top: 15px;
  }
  #cssmenu #menu-button::before {
    display: block;
    content: '';
    position: absolute;
    height: 3px;
    width: 22px;
    border-top: 2px solid #7a8189;
    right: 20px;
    top: 25px;
  }
  #cssmenu ul.open #menu-button::after,
  #cssmenu ul.open #menu-button::before {
    border-color: #fff;
  }
}

感谢您的帮助。

Answer 1

尝试这些修改：

#cssmenu { text-align: center;}
#cssmenu > ul { width: auto; display: inline-block; margin: auto;}

Answer 2

ul {
  width: 100%;
  text-align: center;
}

Answer 3

#cssmenu > ul {
  display: block;
  text-align: center;
}

#cssmenu > ul > li {
  display: inline-block;
  float: none;
}

请注意，（较早的）Internet Explorer对inline-block的支持是伪劣的，应予以考虑。

Answer 4

我通常使用以下方法， 1.设置菜单（或其他元素）的精确宽度， 2.增加保证金。

#cssmenu {
  width: 700px;
  margin-left: auto;
  margin-right: auto;
}

如何将此CSS水平菜单居中？

4 个答案: