知识点:1、字符创不能分行写;
2、div在窗口中居中的方法:让div的left和top分别为:($(window).width()-$("div").width())/2;($(window).height()-$("div").height())/2;
3、当窗口滚动或者调整大小时,让div的left和top分别为在原来的基础上加上滚动距离:$(window).scrollLeft()和$(window).scrollTop()
<!DOCTYPE html>
<html lang="zh-CN"><head> <meta charset="UTF-8"> <style> body{height:2000px;} #login{width:300px;height:300px;border:1px solid #000;position:absolute;} #close{position:absolute;top:0;right:0;} </style> <title>编写弹窗 并居中</title> <script src="jquery.min.js"></script> <script> $(function(){ var bd=$("body"); var btn=$('<input type="button" value="点击">'); bd.append(btn); btn.click(function(){ var log=$('<div id="login"><label for="user">用户名:<input type="text" name="user"></label><br><label for="pass">密 码:<input type="password" name="pass"></label><br><div id="close">X</div></div>'); bd.append(log); $("#close").click(function(){ log.remove(); }); log.css('left',($(window).width()-log.outerWidth())/2); log.css('top',($(window).height()-log.outerHeight())/2); $(window).on("resize scroll",function(){ log.css('left',($(window).width()-log.outerWidth())/2); log.css("top",($(window).height()-log.outerHeight())/2+$(window).scrollTop()); }); });});</script></head><body></body></html>