如何使用javascript使用代理

Question

问题是，当我想从服务器获得响应时，它会给出null

//url of web service        
url="http://www.google.com/ig/calculator?hl=en&q=12INR=?GBP"
var xmlHttp=new xmlHttpRequest();
//object of xml request
xmlHttp.open('GET', url, true);
//get method
xmlHttp.onreadystatechange = function(){
try{
        if (xmlHttp.readyState != 4) 
            return;                                 
        alert(xmlHttp.responseXML);
        var result = xmlHttp.responseXML.documentElement;
        var jsonString = result.childNodes[0].nodeValue;        
        var result1 = jsonParse(jsonString); 
        alert(result1.rhs);
        document.getElementById('results').innerHTML = innerHTML;
            }
    catch(e1){alert("erroe="+e1);}
};
    xmlHttp.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
    xmlHttp.send(null); 

}

Answer 1

除非您的网页已经从www.google.com域投放，否则您无法对www.google.com进行AJAX调用。

https://developer.mozilla.org/en/Same_origin_policy_for_JavaScript