IE8下ajax兼容问题

   function crossDomainAjax(url, successCallback) {

          // IE8 & 9 only Cross domain JSON GET request
          if ('XDomainRequest' in window && window.XDomainRequest !== null) {

              var xdr = new XDomainRequest(); // Use Microsoft XDR
              xdr.open('get', url);
              xdr.onload = function () {
                  var dom = new ActiveXObject('Microsoft.XMLDOM'),
                JSON = $.parseJSON(xdr.responseText);

                  dom.async = false;

                  if (JSON == null || typeof (JSON) == 'undefined') {
                      JSON = $.parseJSON(data.firstChild.textContent);
                  }

                  successCallback(JSON); // internal function
              };

              xdr.onerror = function () {
                  _result = false;
              };

              xdr.send();
          }

          // IE7 and lower can't do cross domain
          else if (navigator.userAgent.indexOf('MSIE') != -1 &&
             parseInt(navigator.userAgent.match(/MSIE ([d.]+)/)[1], 10) < 8) {
              return false;
          }

          // Do normal jQuery AJAX for everything else          
          else {
              $.ajax({
                  url: url,
                  cache: false,
                  dataType: 'json',
                  type: 'GET',
                  async: false, // must be set to false
                  success: function (data, success) {
                      successCallback(data);
                  }
              });
          }
      }

执行回调方法

          crossDomainAjax(url, function (data) {

              var newdata = data.Content;
              var str = "";
              for (var i = 0; i < newdata.length; i++) {
                  str += '<li><a href="http://www.XXX.com/Crawler.aspx?purl=' + encodeURI(newdata[i].Producturl) + '" target="_blank"><div><img src="' + newdata[i].img + '"alt=""/></div><p>' + newdata[i].Name + '</p></a><p class="red">￥' + newdata[i].pric + '</p></li> ';
              }
              if (data.img != "" && data.img != null) {
                  $(".banner img").attr("src", data.img)
              } else {
                  $(".banner").hide();
              }
              document.title = data.title + '- Panli代购';
              callback(parseInt(data.Count));
              $(".content ul").html(str);
          });