ajax跨域请求2次问题处理
当跨域文件中包含header('Access-Control-Allow-Headers:*');时,必须将options请求过滤掉
header('Access-Control-Allow-Origin:*');
header('Access-Control-Allow-Headers:*');
header("Content-type: text/html; charset=UTF-8");
if (strtolower($_SERVER['REQUEST_METHOD']) == 'options') {
exit;
}




