解决ajax跨域请求数据cookie丢失问题

xhrFields: {
 withCredentials: true
 },
 crossDomain: true,
$.ajax({
 type: postType,
 url: url,
 data: postData || '',
 xhrFields: {
 withCredentials: true
 },
 crossDomain: true,
 success: function () {
 successCallback.apply(scope || this, arguments);
 },
 failureCallback: function () {
 failureCallback.apply(scope || this, arguments);
 },
 dataType: dataType
 });

header("Access-Control-Allow-Credentials: true");
header('Access-Control-Allow-Origin: http://m.z.com');