<script src="jquery-1.11.1.min.js" type="text/javascript"></script>
<script type="text/javascript">
  $(function () {
    var alink01 = $(".item > ul");
    alink01.hover(function () {
      //alert div
      var divId = $(this).find("div").attr("id");
      var div = $("#" + divId); //要浮動(dòng)在這個(gè)元素旁邊的層
      div.css("position", "absolute"); //讓這個(gè)層可以絕對(duì)定位
      var self = $(this); //當(dāng)前對(duì)象
      div.css("display", "block");
      var p = self.position(); //獲取這個(gè)元素的left和top
      var x = p.left + self.width(); //獲取這個(gè)浮動(dòng)層的left
      div.css("left", x + 45); //20140916修改
      div.css("top", p.top);
      div.show();
      //mouseenter
      $(this).removeClass("unfocus").addClass("focus");
    },
    function () {
      var divId = $(this).find("div").attr("id");
      var div = $("#" + divId); //要浮動(dòng)在這個(gè)元素旁邊的層
      div.css("display", "none");
      //mouseleave
      $(this).removeClass("focus").addClass("unfocus");
    });
  });
</script>

<div class="leftbody">
  <div class="item">
  <span>全部分類</span>
  <ul class="focus">
    <li ><strong>php</strong> <br />
    php基本語(yǔ)法 php實(shí)例
    </li>
  </ul>
  <ul class="unfocus">
    <li ><strong>java</strong> <br />
    java語(yǔ)法 java面向?qū)ο?
    </li>
  </ul>
  <ul class="unfocus">
    <li ><strong>Python</strong> <br />
    Python語(yǔ)法 Python圖形處理
    </li>
  </ul>
  <ul class="unfocus">
    <li ><strong>javascript</strong> <br />
    javascript幻燈片 javascript網(wǎng)頁(yè)特效
    </li>
  </ul>
  <ul class="unfocus">
    <li ><strong>C#</strong> <br />
    C#桌面應(yīng)用程序 C#網(wǎng)絡(luò)程序
    </li>
  </ul>
  <ul class="unfocus">
    <li ><strong>VC++</strong> <br />
    VC++系統(tǒng)程序開(kāi)發(fā) VC++網(wǎng)絡(luò)程序
    </li>
  </ul>
  <ul class="unfocus">
    <li ><strong>Delphi</strong> <br />
    Delphi桌面程序 Delphi游戲開(kāi)發(fā)
    </li>
  </ul>
  </div>
</div>