IOS在类别中添加属性

#import <Foundation/Foundation.h>
#import "Person.h"
#import "Person+Add.h"

int main(int argc, const char * argv[])
{

@autoreleasepool {

// insert code here...
NSLog(@"Hello, World!");

Person *person = [[Person alloc] init];
person.name = @"张三";

[person setType:@"NSString *"];
[person setValue:@"hehe"];

NSLog(@"%@", [person value]);

[person print];

}
return 0;
}

#import <Foundation/Foundation.h>

@interface Person : NSObject

@property (nonatomic, copy)NSString *name;

@end

#import "Person.h"

@implementation Person

@end

#import "Person.h"

@interface Person (Add)

- (void)print;
- (void)setType:(NSString *)type;
- (void)setValue:(id)value;
- (id)value;

@end

#import "Person+Add.h"
#import <objc/runtime.h>

@implementation Person (Add)

static NSString *typeStr;

- (void)print {
NSLog(@"%@", self.name);
}

- (void)setType:(NSString *)type {
typeStr = type;
}

- (void)setValue:(id)value {
objc_setAssociatedObject(self, (__bridge const void *)(typeStr), value, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}

- (id)value {
id pro = objc_getAssociatedObject(self, (__bridge const void *)(typeStr));
return pro;
}

@end