解决跨域问题
// 指定允许其他域名访问
//header('Access-Control-Allow-Origin: '.$_SERVER['HTTP_ORIGIN']);
header('Access-Control-Allow-Origin: *');
// 响应类型
header('Access-Control-Allow-Methods:POST');
// 响应头设置
header('Access-Control-Allow-Headers:x-requested-with,content-type');
//允许cookie 跨域（跨域资源共享）
header('Access-Control-Allow-Credentials: true');

//万能解决跨域问题
header("Access-Control-Allow-Origin: *");
header('Access-Control-Allow-Methods:*');
header('Access-Control-Allow-Headers:*');
header("Access-Control-Request-Headers: *");