iframe的用法與註意事項-SEO優化知識---TheMindSEM Search Engine Optimization--專業網路行銷及網站SEO優化排名服務

iframe的用法與註意事項

aa.htm

运行代码框
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html <a href="http://edu.mycodes.net/search.aspx?Where=title&cid=0&Keyword=xml&x=21&y=8" title="">xml</a>ns="http://www.w3.org/1999/xhtml" > <head> <title>Untitled Page</title> <style type="text/css">  </style> </head> <body> <iframe id="ifr" name="ifr" width="100%" height="500" src="bb.htm"></iframe> </body> </html> <script language="javascript" type="text/javascript"> var aa_value="I'm a variant in Top window!"; var ifr_id=document.getElementById("ifr"); var ifr_window=window.frames["ifr"]; alert("Alert from Top window : Can't get iframe's variant by ifr_id, it will return :" + ifr_id.bb_var); alert("Alert from Top window : Can't get iframe's DOM model by ifr_id ,it will return :" + ifr_id.window); alert("Alert from Top window : Get src from id :" + ifr_id.src); alert("Alert from Top window : Get href from window:" + ifr_window.document.location.href); //由于bb.htm可能还未装载完成,所以,下冇的可能引发错误 //调用iframe内的函数 ifr_window.bb(); //调用iframe内的变量 alert("Alert from Top window : " + ifr_window.bb_var); // alert("Alert from Top Window :" + ifr_window.document.body.innerHTML); function aa(msg){ alert("I'm alerting from Top window ,and I received a msg:\n" + msg); } </script>
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bb.htm

运行代码框
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html <a href="http://edu.mycodes.net/search.aspx?Where=title&cid=0&Keyword=xml&x=21&y=8" title="">xml</a>ns="http://www.w3.org/1999/xhtml" > <head> <title>sub frame</title> <style type="text/css">  </style> </head> <body> I'm a sub frame! <br /> ...<br /> ...<br /> ...<br /> ...<br /> ...<br /> ...<br /> ...<br /> ...<br /> ...<br /> ...<br /> ...<br /> ...<br /> ...<br /> ...<br /> ...<br /> ...<br /> ...<br /> ...<br /> ...<br /> ...<br /> ...<br /> ...<br /> ...<br /> ...<br /> ...<br /> ...<br /> ...<br /> ...<br /> ...<br /> ...<br /> ...<br /> ...<br /> ...<br /> ...<br /> ...<br /> ...<br /> ...<br /> ...<br /> ...<br /> ...<br /> ...<br /> ... </body> </html> <script language="javascript" type="text/javascript"> var bb_var="I'm a variable in ifr"; function bb(){ alert("Alert from iframe :I'm frame ifr's function") } //获取父页面的变量 alert("Alert from iframe parent.ifr_id::" + parent.ifr_id); alert("Alert from iframe parent.aa_value : " + parent.aa_value); //通过父页面的ifr_id来改变 iframe的高度 alert("Alert from iframe : ifr's clientHeight :" +document.body.clientHeight); parent.ifr_id.height=document.body.clientHeight; alert("Alert from iframe : ifr's scrollHeight : " + document.body.scrollHeight); //调用父窗体的函数: parent.aa("I will calling a function which is Top window's "); //改变父窗体的标题: alert("Alert from iframe : I will changing Top window's title"); top.document.title="The title value changed"; //通过父窗体的ifr_id来改变的border 与scrolling alert("Alert from iframe : I will change my border and scrolling :"); top.ifr_id.border=0; top.ifr_id.scrolling="no"; </script>
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好多同志對iframe是如何控制的,並不是十分了解,基本上還處於一個模糊的認識狀態.

注意兩個事項,ifr是一個以存在的iframe的ID和NAME值:
 document.getElementById(“ifr”);
 window.frames[“ifr”];

要想使用iframe內的函數,變量就必須通過第二種方法.因為它取的是一個完整的DOM模型(不知道這樣說對不對).第一種方法只是取出了一個OBJECT而已.

如果只想改變iframe的src或者border , scrolling等attributes(與property不是一個概念,property是不能寫在標籤內的,比如:scrollHeight,innerHTML等),就需要用到第一種方法.

如果想取得iframe的頁面(不是iframe本身),就需要使用第二種方法,因為它取得的是一個完整的DOM模型,比如想得到iframe的document.body的內容,就只能用第二種方法.

還要注意的是,如果在iframe的頁面未完全裝入的時候,調用iframe的DOM模型,會發生很嚴重的錯誤,所以,你要準備一個容錯模式.

下面是示例,一個是aa.htm,一個是bb.htm,請先考到本地在運行,原因不用我在說了吧!

iframe的用法與註意事項

SEO優化知識