CakePHP：无法修改标头信息 - 已经发送的标头
完成错误：
Warning (2): Cannot modify header information - headers already sent by (output started at /Applications/XAMPP/xamppfiles/htdocs/trunk/dafe/cake/basics.php:355) [CORE/cake/libs/controller/controller.php, line 743]
据我所知，在我尝试重定向后会发生这种情况。我知道它是由空格引起的，但我无法在任何地方找到它，这个错误往往在哪里？
As far as I can tell it happens after I try to redirect. I know it's caused by a whitespace but I can't find it anywhere, where does this error tend to be?
编辑：忘记提及，这个问题只发生在我的Mac，我的Windows合作伙伴没有这个问题，重定向适合他。
Forgot to mention, this problem only happens on my Mac, my partner working on windows does not have this issue, redirection works appropriately for him.
我知道的两种可能性：
A.关闭PHP标签后，你可能会有一些空格？> 。
Two possibilities I know of:
A. You might have some whitespace after the class closing PHP tag ?>.
B.您正在尝试在处理数据/逻辑期间 echo / pr（）（当它重定向，保存到数据库等时）
B. You are trying to echo/ pr() during the processing of the data/ logic (-while it's redirecting, saving to the database, etc)