ajax 跨域 解决方法 防坑

header("Access-Control-Allow-Origin: *");  

header("Access-Control-Allow-Methods: GET, POST");  

header("Access-Control-Allow-Headers: Origin, No-Cache, X-Requested-With, If-Modified-Since, Pragma, Last-Modified, Cache-Control, Expires, Content-Type, X-E4M-With");