How to store blocks in properties in Objective-C?

objective-c objective-c-blocks
Piotr Czapla picture Piotr Czapla · Nov 2, 2010 · Viewed 40.2k times · Source

I'd like to store objective-c block in a property for later use. I wasn't sure how to do it so I googled a bit and there is very little info about the subject. But I've managed to find the solution eventually and I've thought that it might be worth sharing for other newbies like me.

Initially I've thought that I would need to write the properties by hand to use Block_copy & Block_release.

Fortunately I've found out that blocks are NSObjects and - copy/- release is equivalent to Block_copy/Block_release. So I can use @property (copy) to auto generate setters & getters.

Answer

Dave DeLong picture Dave DeLong · Nov 2, 2010

Edit: updated for ARC

typedef void(^MyCustomBlock)(void);

@interface MyClass : NSObject

@property (nonatomic, copy) MyCustomBlock customBlock;

@end

@implementation MyClass

@end

MyClass * c = [[MyClass alloc] init];
c.customBlock = ^{
  NSLog(@"hello.....");
}

c.customBlock();

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