使用XDomainRequest将参数发布到ASP.NET MVC控制器

Question

我使用XDomainRequest将数据发送到MVC控制器，但参数为空

    if (wQuery.browser.msie && window.XDomainRequest) {
    // Use Microsoft XDR
    var xdr = new XDomainRequest();
    xdr.open("post", url);
    xdr.onload = function () {      
        updateData(xdr.responseText);
    };
    var data1= {css:"cssvalue", culture:"value"};
    var params = '';
    for (key in data1) {
           params = params+'&'+key+'='+data1[key];
    }
    xdr.send(params);
   } else {
     ....}


 public ActionResult Index(string css, string culture)
        {
              css and culture = null here
        }