A tool to create weakly property in category. explain
一个在分类中创建弱引用属性的工具，原文链接。
// in a category...
#import "MUAssociation.h"
// @property (nonatomic, weak) id someProperty; // write in .h file
@implementation SomeClass (SomeCategory)
- (void)setSomeProperty:(id)someProperty {
[self setAssociatedObject:someProperty forKey:@"someProperty" association:NSAssociationWeak isAtomic:NO];
}
- (id)someProperty {
return [self associatedObjectForKey:@"someProperty"];
}
@end