带炫酷鼠标滑过特效的垂直导航菜单

这是一款带炫酷鼠标滑过特效的垂直导航菜单特效。该菜单特效中，当鼠标滑过菜单项时，会有一个背景遮罩层跟着鼠标移动，效果非常炫酷。

使用方法

HTML结构

该垂直导航菜单的HTML结构非常简单：

<div class="menu-container">
  <menu>
    <menuitem>
    <img src="img/144211.svg" />
    avocado
    </menuitem>
    <menuitem>
    <img src="img/144207.svg" />
    banana
    </menuitem>
    <menuitem>
    <img src="img/144210.svg" />
    cherry
    </menuitem>
    <menuitem>
    <img src="img/144198.svg" />
    eggplant
    </menuitem>    
  </menu>
  <div class="sliding-bar"></div>
</div>   
                

CSS样式

为垂直导航菜单添加一些必要的CSS样式：

.menu-container {
  display: inline-block;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translateX(-50%) translateY(-50%);
  background-color: #fff;
  z-index: 0;
  box-shadow: 0 5px 10px rgba(0, 0, 0, 0.2);
}
.menu-container menu {
  display: block;
  position: relative;
  width: 15em;
  padding: .25em;
  border: 2px solid #c99;
  margin: 0;
  z-index: 2;
}
.menu-container menu menuitem {
  display: block;
  height: 4em;
  line-height: 4em;
  padding: 0 1em;
  cursor: pointer;
  background: transparent;
  text-align: left;
  color: #666;
  font-weight: 500;
  letter-spacing: .02em;
}
.menu-container menu menuitem:hover {
  color: #000;
}
.menu-container menu menuitem img {
  padding-right: 1em;
  height: 2em;
  vertical-align: middle;
}
.menu-container .sliding-bar {
  position: absolute;
  background-color: #aef;
  transition: all .2s ease;
  z-index: 1;
  opacity: 0;
}                  
                

JavaScript

该垂直导航菜单通过jQuery来制作鼠标互动效果。

$(window).ready(function(){
  initMenu();
});

$('menuitem').hover(function(){
  var offset = $(this).offset();
  $('.sliding-bar').offset(offset);
});

$('menu').hover(function(){
  $('.sliding-bar').css({opacity:1});
},function(){
  $('.sliding-bar').css({opacity:0});
})


var initMenu = function () {
  var $initElem = $('menuitem:first-of-type');
  var initOffset = $initElem.offset();
  var initSize = {
    width: $initElem.css('width'),
    height: $initElem.css('height')    
  }
  $('.sliding-bar')
    .offset(initOffset)
    .css(initSize)
}