监听键盘通知

[[NSNotificationCenterdefaultCenter]addObserver:self

selector:@selector(keyboardWillShow:)

name:UIKeyboardWillShowNotification

object:nil];

[[NSNotificationCenterdefaultCenter]addObserver:self

selector:@selector(keyboardShow:)

name:UIKeyboardDidShowNotification

object:nil];

[[NSNotificationCenterdefaultCenter]addObserver:self

selector:@selector(keyboardWillHide:)

name:UIKeyboardWillHideNotification

object:nil];

[[NSNotificationCenterdefaultCenter]addObserver:self

selector:@selector(keyboardHide:)

name:UIKeyboardDidHideNotification

object:nil];