#import <Foundation/Foundation.h>#define CHILD_WEAK_NOTIFC @"childe_week"@interface Child : NSObject@property (nonatomic,assign) int age;@property (nonatomic,assign) NSInteger sleep;@end

#import "Child.h"@implementation Child-(id) init{    self=[super init];    if(self!=nil){        _sleep=100;        [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(timeAction:) userInfo:nil repeats:YES];    }    return self;}-(void) timeAction:(NSTimer *) timer{    _sleep-=2;    NSLog(@"%ld",_sleep);    if(_sleep<90){        //发送通知        [[NSNotificationCenter defaultCenter] postNotificationName:CHILD_WEAK_NOTIFC object:[NSNumber numberWithInteger:_sleep]];        [timer invalidate];    }}@end

#import <Foundation/Foundation.h>@interface Father : NSObject@end

#import "Father.h"#import "Child.h"@implementation Father-(id)init{    self=[super init];        if(self!=nil){        //接收通知        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(weakNotification:) name:CHILD_WEAK_NOTIFC object:nil];    }    return self;}-(void)weakNotification:(NSNotification *) notification{         NSLog(@"sdkjflskdjf");    NSNumber *number=notification.object;        NSLog(@"%@",number);}@end

Child *child=[[Child alloc]init];        Father *father=[[Father alloc]init];        NSLog(@"%@",child);        [[NSRunLoop currentRunLoop] run];