随页面滚动显示/隐藏窗口固定位置元素_html/css_WEB-ITnose

<p id="selected-case-count"><span class='form-control'>已选: <span class="casecount">0</span></span></p>

p#selected-case-count{      position:fixed;  /*固定元素位置*/      top:2px;  /*距顶端举例*/      right:40px; /*距右侧位置*/      color:red; }

$(function() {    $("#selected-case-count").hide();});var preTop=0;var currTop=0;$(function () {    $(window).scroll(function(){        currTop=$(window).scrollTop();        if(currTop<preTop){            $("#selected-case-count").fadeOut(200);        }elseif ($(window).scrollTop()>600){            $("#selected-case-count").fadeIn(500);        }else{            $("#selected-case-count").fadeOut(500);        }        preTop=$(window).scrollTop();    });});