问题
I am getting following warning on OS X 10.9 console at the time of nib load(NSWindowController).
Invalid color System, labelColor (warning given only once)
I am using Xcode 6 and OS X 10.10 to compile my code. Most probably this warning is coming because of NSColor exposes new system colors in 10.10 for static text and related elements: labelColor, secondaryLabelColor, tertiaryLabelColor, and quaternaryLabelColor.
How to fix this warning?
回答1:
Change your textfield's color in your xib file from:
<color key="textColor" name="labelColor" catalog="System" colorSpace="catalog"/>
to:
<color key="textColor" name="textColor" catalog="System" colorSpace="catalog"/>
Since "labelColor" is not a formal color name in OSX 10.9.
回答2:
The warning is there to inform you the color is not available in 10.9 (or below). You could simply check the OS version (using AppKit constant NSAppKitVersionNumber) and handle the color properly according to the version.
Good reading: Apple Developer Guide on SDK Compatibility
来源：https://stackoverflow.com/questions/27507727/invalid-color-system-labelcolor-warning-given-only-once