javascript中top的作用

悠悠 2022-04-11 14:13 692阅读 0赞

top作用是取得最顶层框架对象

A.html

![None.gif][] <! DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd" >   
![None.gif][] < html  xmlns ="http://www.w3.org/1999/xhtml" >   
![None.gif][] < head >   
![None.gif][] < meta  http-equiv ="Content-Type"  content ="text/html; charset=gb2312"   />   
![None.gif][] < title > prototype test </ title >   
![None.gif][] </ head >   
![None.gif][] < body >   
![None.gif][] < iframe  src ="b.html" ></ iframe >   
![ExpandedBlockStart.gif][] < script  language ="javascript" >   
![InBlock.gif][]var topstr = "my top";  
![InBlock.gif][]    alert(a.html='\+top.location.href);  
![InBlock.gif][]</script>  
![InBlock.gif][]  
![InBlock.gif][]</body>  
![InBlock.gif][]</html>B.html

![None.gif][] <! DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd" >   
![None.gif][] < html  xmlns ="http://www.w3.org/1999/xhtml" >   
![None.gif][] < head >   
![None.gif][] < meta  http-equiv ="Content-Type"  content ="text/html; charset=gb2312"   />   
![None.gif][] < title > prototype test </ title >   
![None.gif][] </ head >   
![None.gif][] < body >   
![None.gif][] < iframe  src ="c.html" ></ iframe >   
![ExpandedBlockStart.gif][] < script  language ="javascript" >   
![InBlock.gif][]  
![ExpandedBlockEnd.gif][]alert('b.html='\+top.location.href\+";a.html.topstr="\+top.topstr);//top.topstr可取a.html(顶层框架参数)的topstr变量  
![None.gif][] </ script >   
![None.gif][]  
![None.gif][] </ body >   
![None.gif][] </ html >

C.html

![None.gif][] <! DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd" >   
![None.gif][] < html  xmlns ="http://www.w3.org/1999/xhtml" >   
![None.gif][] < head >   
![None.gif][] < meta  http-equiv ="Content-Type"  content ="text/html; charset=gb2312"   />   
![None.gif][] < title > prototype test </ title >   
![None.gif][] </ head >   
![None.gif][] < body >   
![None.gif][]  
![ExpandedBlockStart.gif][] < script  language ="javascript" >   
![InBlock.gif][]  
![ExpandedBlockEnd.gif][]alert('c.html='\+top.location.href\+";a.html.topstr="\+top.topstr);//top.topstr可取a.html(顶层框架参数)的topstr变量  
![None.gif][] </ script >   
![None.gif][]  
![None.gif][] </ body >   
![None.gif][] </ html >

b.html中的top=parent c.html中的top=parent.parent

[http://blog.csdn.net/good\_youth/article/details/2079416][http_blog.csdn.net_good_youth_article_details_2079416]

[None.gif]: /images/20220411/39e7e2b367184aa68f93308ac47e61e4.png
[ExpandedBlockStart.gif]: /images/20220411/0eebededbc1241418d1d9d3b3f50fd10.png
[InBlock.gif]: /images/20220411/5e9d15c8673a4cc6b2e38098b3685ba1.png
[ExpandedBlockEnd.gif]: /images/20220411/0611180ae2744f2b9872f1ddfa702726.png
[http_blog.csdn.net_good_youth_article_details_2079416]: http://blog.csdn.net/good_youth/article/details/2079416