1）在iframe中查找父页面元素的方法：
$('#id', parent.document)
2）在iframe中调用父页面中定义的方法和变量：
parent.method
parent.value
3）实例
父页面
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="IframeDemo._Default" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server"><title></title><script language="javascript" type="text/javascript" src="jquery-1.5.1.min.js"></script><script language="javascript" type="text/javascript">var hello = 'hello';function getHelloWorld() {alert('hello world');}</script>
</head>
<body><form id="form1" runat="server"><div><div id="default" style=" width:200px; height:400px; float:left;">default.aspx</div><iframe id="iframeid" src="IFrame.aspx" style=" width:400px; height:400px; float:left;"></iframe></div></form>
</body>
</html>
子页面
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="IFrame.aspx.cs" Inherits="IframeDemo.IFrame" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server"><title></title><script language="javascript" type="text/javascript" src="jquery-1.5.1.min.js"></script><script language="javascript" type="text/javascript">$(function() {//在iframe中查找父页面元素alert($('#default', window.parent.document).html());//在iframe中调用父页面中定义的方法parent.getHelloWorld();//在iframe中调用父页面中定义的变量alert(parent.hello);});</script>
</head>
<body><form id="form1" runat="server"><div id="iframe">IFrame.aspx</div></form>
</body>
</html>