注册消息

[[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(方法) name:@"消息名字" object:nil];

方法实现

-(void)方法:(NSNotification *)notfication{

//获取传递的数据

NSDictionary * dataDic = notfication.object;

}

发布消息

[[NSNotificationCenter defaultCenter]postNotificationName:@"消息名字" object:传回的东西];

键盘的消息使用

[[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(keyBoardDicChanged:) name:UIKeyboardWillChangeFrameNotification object:nil];

方法实现

-(void)keyBoardDicChanged:(NSNotification *)notifi{

//可以先打印notifi开看看有什么消息名字

CGRect endRect = [[notifi.userInfo objectForKey:@"UIKeyboardFrameEndUserInfoKey"] CGRectValue];

......//屏幕在键盘改变的时候重新布局

[self.view layoutIfNeeded];

}