Objective-C中的发通知的（Notification)

第一个页面进来后，先注册监听

@implementation ViewController- (void)viewDidLoad
{[super viewDidLoad];//先在通知中心注册[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(doSomething:) name:NOTIFICATION_MESSAGE object:nil];
}- (void)viewWillDisappear:(BOOL)animated
{[super viewWillDisappear:YES];// [[NSNotificationCenter defaultCenter] removeObserver:self];}-(void)doSomething:(NSNotification *)notification
{//接受消息NSDictionary *Info = [notification userInfo];//输出收到的信息NSLog(@“消息收到：%@", Info[@"notification"]);
}

第二个页面进来后点击button 然后发消息

@implementation ChatViewController- (void)viewDidLoad
{[super viewDidLoad];[self initContentView];
}- (void)initContentView
{UIButton *_commitBtn = [[UIButton alloc]initWithFrame:CGRectMake(15, 179, kDEVICEWIDTH-30, 45)];_commitBtn.backgroundColor = [UIColor grayColor];[_commitBtn addTarget:self action:@selector(commitClick) forControlEvents:UIControlEventTouchUpInside];[_commitBtn setTitle:@"发消息" forState:UIControlStateNormal];_commitBtn.titleLabel.textColor = [UIColor whiteColor];_commitBtn.layer.cornerRadius = 4;[self.view addSubview:_commitBtn];}- (void)commitClick
{[self sendMessage];
}#pragma mark - NSNotification method-(void)sendMessage
{//把要发送的信息放入字典中NSDictionary *message = @{@"notification" : @“NSNotification消息测试通过！”};//创建通知对象NSNotification * notification = [NSNotification notificationWithName:NOTIFICATION_MESSAGE object:self userInfo:message];//向通知中心发送消息（发布消息）//[[NSNotificationCenter defaultCenter] postNotificationName:NOTIFICATION_MESSAGE object:nil];//向通知中心发送消息（发布消息）[[NSNotificationCenter defaultCenter] postNotification:notification];
}