How can I disable spell checking for an NSTextView? In particular, the red lines that are automatically drawn. I know about the "Continuous Spell Checking" option in Xcode, and every option I have found in the documentation related to spell checking doesn't seem to take the red lines away.
Select NSTextView (doubleClick in IB on it because NSTextView is in NSScrollView by default or select it in Document Outline) and go to Attributes Inspector -> Linguistics -> and uncheck Continous Spell Checking here:
Result:
I don't know what you tried, but [self.textView setContinuousSpellCheckingEnabled:NO]; worked for me.
After unsetting continuousSpellCheckingEnabled clean your build folder and run again. Seems as though it is holding onto the setting between builds (quite surprisingly!). Your observation that changing the property name solved the issue led me to this solution -- still an issue almost five years after you asked.
来源：https://stackoverflow.com/questions/11806146/completely-disable-nstextview-spell-checking