js鼠标悬浮出现遮罩层的方法

本文实例讲述了js鼠标悬浮出现遮罩层的方法。分享给大家供大家参考。具体实现方法如下：

html页面代码：

<ul class="site-tag fl">  

        <li><a data-title="科学" href="#"><i style="background-image: url(images/xiaozhan/main_ojls_1aa6000200891260.jpg)">  

        </i><span class="tag-tit">科学</span> </a></li>  

        <li><a data-title="动漫" href="#"><i style="background-image: url(images/xiaozhan/main_NH8v_2e310001ebd1118e.jpg)">  

        </i><span class="tag-tit">动漫</span> </a></li>  

        <li><a data-title="生活" href="#"><i style="background-image: url(images/xiaozhan/main_OtnR_43a60000050a118c.jpg)">  

        </i><span class="tag-tit">生活</span> </a></li>  

        <li><a data-title="插画" href="#"><i style="background-image: url(images/xiaozhan/main_UD3z_2e510002074f118e.jpg)">  

        </i><span class="tag-tit">插画</span> </a></li>  

        <li><a data-title="音乐" href="#"><i style="background-image: url(images/xiaozhan/main_krFk_6323000018bd125d.jpg)">  

        </i><span class="tag-tit">音乐</span> </a></li>  

        <li><a data-title="自然" href="#"><i style="background-image: url(images/xiaozhan/main_UAbs_764f0001ff601190.jpg)">  

        </i><span class="tag-tit">自然</span> </a></li>  

</ul>

<script type="text/javascript">  

        $(function () {  

            //遮罩层，鼠标移动上去高度变化，变清晰  

            var $site_li = $(".site-tag li");  

            $site_li.hover(function () {  

                var indexs = $site_li.index(this);  

                $(this).css("height", "90").find(".tag-tit").css("top", "30").css("color", "#fff");  

                //获取当前点击li元素在全部li元素中的索引  

                //alert(indexs+1);  

                $(this).prev().css("height", "30");  

                $(this).next().css("height", "30");  

            }, function () {  

                $site_li.css("height", "50");  

            });  

        });  

 </script>

ul li{ list-style:none;}  

.site-tag{ width:200px; overflow:hidden; z-index:5;}  

.site-tag li{ position:relative; width:200px; height:50px; margin-bottom:1px; overflow:hidden;   

transition:height 0.5s ease; -webkit-transition:height 0.5s ease;   

-moz-transition:height 0.5s ease; -o-transition:height 0.5s ease;}  

.site-tag li a { color: #666; font-size: 16px; font-weight: bold;line-height: 50px;}  

.site-tag li i{ display:block; height:90px; background-position:center center;  

opacity:0.3; filter:alpha(opacity=3);  /*设置透明度*/  

-webkit-transition:opacity 0.5 ease;   /**/  

-webkit-filter:grayscale(60%);         /**/  

}  

.site-tag li:hover i { opacity:0.9; -webkit-filter:grayscale(0%); transition:opacity 0.5s ease;}  

.tag-tit{ display:block; height:100px; width:700px; color:#666; font-size:14px;}                   

.site-tag li .tag-tit{ position:absolute; top:0px; left:10px; text-shadow:1px 1px 1px rgb(0,0,0,0.1);}  

a:hover .tag-tit{ text-shadow:1px 1px 1px rgb(0,0,0,0.5);}

希望本文所述对大家的javascript程序设计有所帮助。