当用户第一次访问网站时候，此时没有设置cookies参数,并且设置过期，弹出显示对话框，弹完之后，设置cookies参数”popped=yes;expires=”+date.toGMTString()”，第二次加载时候，判断存在这个参数，则跳过加载对话框，cookies失效后，浏览器会自动删除失效的参数
代码：JS/css引入
<link rel=”stylesheet” href=”//apps.bdimg.com/libs/jqueryui/1.10.4/css/jquery-ui.min.css”>
<script src=”//apps.bdimg.com/libs/jquery/1.10.2/jquery.min.js”></script>
<script src=”//apps.bdimg.com/libs/jqueryui/1.10.4/jquery-ui.min.js”></script>
<script>
$(function() {
if (get_cookie(‘popped’)==”){
$(“#dialog-modal”).show();
$( “#dialog-modal” ).dialog({
height: 410,
width: 815,
modal: true
});
var date=new Date();
date.setTime(date.getTime()+12*60*60*1000); //设置date为当前时间+30分
document.cookie=”popped=yes;expires=”+date.toGMTString();
}else{
$(“#dialog-modal”).hide();
}
});
function get_cookie(Name) {
var search = Name + “=”
var returnvalue = “”;
if (document.cookie.length > 0) {
offset = document.cookie.indexOf(search)
if (offset != -1) {
offset += search.length
end = document.cookie.indexOf(“;”, offset);
if (end == -1)
end = document.cookie.length;
returnvalue=unescape(document.cookie.substring(offset, end))
}
}
return returnvalue;
}
</script>
<div id=”dialog-modal” title=”关注公众号（Java杂记），领取免费的学习资源，目前受益良多” style=”width: auto;min-height: 0px;max-height: none;height: 360px;display:none;”>
<p><img src=”http://www.liuhaihua.cn/wp-content/uploads/2018/07/888.png” data-baiduimageplus-ignore data-tag=”bdshare”/></p>
</div>