1. Dynamic to add method to NSObject

@interface NSObject (CategoryWithProperty)

@property (nonatomic, strong) NSObject *property;

@end

@implementation NSObject (CategoryWithProperty)

– (NSObject *)property {

return objc_getAssociatedObject(self, _cmd);

}

– (void)setProperty:(NSObject *)value {

objc_setAssociatedObject(self, @selector(property), value, OBJC_ASSOCIATION_RETAIN_NONATOMIC);

}

2. Dynamic extension attributes

#import “UILabel+Associate.h”

#import <objc/runtime.h>

@implementation UILabel (Associate) static char flashColorKey;

– (void) setFlashColor:(UIColor *) flashColor{

objc_setAssociatedObject(self, &flashColorKey, flashColor, OBJC_ASSOCIATION_RETAIN_NONATOMIC);

}

– (UIColor *) getFlashColor{

return objc_getAssociatedObject(self, &flashColorKey);

}

@end