wordpress后台Warning:Cannot modify header information在后台更新文章的时候会显示这个Warning:Cannot modify header information - headers already sent by (output started at D:\APMServ5.2.6\www\htdocs\wp\wp-content\themes\yuandong\functio

wordpress后台Warning:Cannot modify header information
在后台更新文章的时候会显示这个Warning:Cannot modify header information - headers already sent by (output started at D:\APMServ5.2.6\www\htdocs\wp\wp-content\themes\yuandong\functions.php:1) in D:\APMServ5.2.6\www\htdocs\wp\wp-includes\pluggable.php on line 934
请问怎么解决

把functions.php编码改成无bom,