Why am I getting a “Title set but using a system Identifier” warning?

问题

I get the following warning:

MainStoryboard.storyboard: Title set but using a system Identifier (These attributes are mutually exclusive; the Title will be ignored)

I have a manually placed toolbar on my storyboard with a Title and a Cancel button. What's wrong about that?

回答1:

Are you adding a title to the Cancel button (e.g. “Cancel”)?

You don’t need to do this as setting the bar button item as a system bar button item (like Cancel) will automatically set the title—and it’ll be localized for you.

来源：https://stackoverflow.com/questions/15466451/why-am-i-getting-a-title-set-but-using-a-system-identifier-warning