Unable to compile code when working with CALayer

Question

For some reason, I get linker errors when trying to use CALayer:

"_OBJC_CLASS_$_CALayer", referenced from: 

I have imported the following headers:

 #import <Foundation/Foundation.h> #import <UIKit/UIKit.h> #import <QuartzCore/QuartzCore.h> 

the code:

 arrowImage = [[CALayer alloc] init]; 

Answer 1

Make sure you also add the QuartzCore structure to your goal. Just importing a title is not enough.

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