通知(Notification)這功能真是神奇，讓人不必時時刻刻去注意某個元件的動靜，當我們登記要得知該元件的動靜之後，只要它出現我們想要的行為，馬上就有人會通知我們，接著就能立刻採取行動！
猜猜看，我要對它做什麼？
在這裡我想觀察虛擬鍵盤的動靜，而且指明是它出現和隱藏的時候，要立刻通知我！
/**
Theme: Notification of keyboard to show/hide
IDE: Xcode 5
Language: Objective C
Date: 103/03/20
Author: HappyMan
Blog: https://cg2010studio.wordpress.com/
*/
// Listen for keyboard appearances and disappearances
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(keyboardDidShow:)
name:UIKeyboardDidShowNotification
object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(keyboardDidHide:)
name:UIKeyboardDidHideNotification
object:nil];
- (void)keyboardDidShow: (NSNotification *) notif{
// Do something here
}
- (void)keyboardDidHide: (NSNotification *) notif{
// Do something here
}
我執行範例的效果就是，在還沒有輸入完畢，也就是虛擬鍵盤出現而沒有消失，我就不讓你離開ＸＤ～
要做完才能離開喲：Ｐ
105/02/01加碼
我們想要輸入框跟著鍵盤上來，就可以寫這樣⋯⋯
- (void)keyboardDidShow:(NSNotification *)notification
{
// 取得鍵盤高度
NSDictionary *info = [notification userInfo];
CGSize kbSize = [[info objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue].size;
CGFloat deltaHeight = kbSize.height;
UIEdgeInsets insets = UIEdgeInsetsMake(0, 0, deltaHeight, 0);
self.tableView.contentInset = insets;
// Table View滾動至輸入框
self.tableView.contentOffset = CGPointMake(0, self.tableView.contentSize.height - deltaHeight);
}
- (void)keyboardDidHide:(NSNotification *)notification
{
UIEdgeInsets insets = UIEdgeInsetsMake(0, 0, 0, 0);
self.tableView.contentInset = insets;
}
逍遙文工作室 
隨意留個言吧：）～