通知的機制是一對多,而block和delegate的機制是一對一,通知是好用,但小伙伴麼要記得通知比較耗性能哦~~~

誰要發送消息,誰就發出通知,誰要接受消息,誰就銷毀通知.

下面直接來看代碼:

//發出通知 [[NSNotificationCenter defaultCenter] postNotificationName:@"notification" object:image]; //誰接受通知 誰就銷毀通知 - (void)viewDidLoad { [super viewDidLoad];

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(valueChanged:) name:@"notification" object:nil];

}

- (void)valueChanged:(NSNotification *)notification{ // object 就是傳過來的參數 self.imgView.image = notification.object;
}
//在對象銷毀的時候移除通知
-(void)dealloc{
[[NSNotificationCenter defaultCenter] removeObserver:self];
}