日期:2014-05-16  浏览次数:21012 次

ajax跨域访问和产生的原因
document.domain = "css88.com";

var createAjaxIframe={
	appIframe: function(iframeId, iframeSrc){
		var iframe = document.createElement("iframe");
		iframe.src = iframeSrc// "http://css88.com/demo/domain/iframe.html";
		iframe.id = iframeId;
		iframe.style.display = "none";
		if (iframe.attachEvent) {
			iframe.attachEvent("onload", function(){
				createAjaxIframe.domainAjax(iframeId);
			});
		}else {
			iframe.onload = function(){
				createAjaxIframe.domainAjax(iframeId);
			};
		}
		document.body.appendChild(iframe);
	},
	domainAjax: function(iframeId){
		var iframeDom = document.getElementById(iframeId).contentWindow.$;
		iframeDom.getJSON("http://css88.com/demo/iframe-domain/city.html", function(date){
			var cityOption = "";
			for (i = 0; i < date.length; i++) {
				cityOption += date[i].c_name + "--" + date[i].c_value + "<br />"
			}
			$("#test").html(cityOption);
		});
	}
	
};
createAjaxIframe.appIframe("iframe","http://css88.com/demo/iframe-domain/iframe.html");

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?使用<script>标签解决ajax跨域:

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这个方法是利用<script>标签中的src来query一个aspx获得response,因为<script>标签的src属性不存在跨域的问题。

举个例子来让大家看得更清楚一点吧:

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<!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>
    <title>Ajax跨域问题</title>
    <script type="text/javascript" src="" id="getAspx">
    </script>
    <script type="text/javascript">
        function get(url) {
            var obj = document.getElementById("getAspx");
            obj.src = url;
            (obj.readStatus == 200)
            {
                alert(responseVal);//如果成功,会弹出Dylan
            }
        }
        function query() {
            get(getDemo.aspx);
        }
    </script>
</head>
<body>
<input type="button" value="Ajax跨域测试" onclick="query();"/>
</body>
</html>
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getDemo.aspx后台代码:

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using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace LearnJS
{
    public partial class getDemo : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            Response.Write("var responseVal='Dylan'");
        }
    }
}

?这个方法又叫做ajaj或者ajax without xmlHttprequest,把x换成了j,是因为使用了<script>标签而没有用到xml和xmlHttprequest的缘故。这种方法似乎有点“另类”,哈哈。

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jquery解决ajax跨域问题:

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<html>
<head>
<title>JQuery学习</title>
<script src="jquery-1.4.2.min.js" type="text/javascript"></script>
<script type="text/javascript">
$(document).ready(function(){
    var oBtnTest = $("#btnTest");
    oBtnTest.click(function(){
        oBtnTest.disabled = true;    
        var oResult = $("#result");
        oResult.html("loading").css("color","red");
        jQuery.getScript("http://www.csdn.com/test/js.txt", 
        function(){            
            oResult.html("name:" + Dylan.name + "<br/>email:" + Dylan.email).css("color","black");            
            oBtnTest.disabled = false;            
        });         
    });    
});    
</script>
</head>
<body>
<button id="btnTest">BtnTest</button>
<div id="result"></div>
</body>