键盘状态改变的时候,系统会发出一些特定的通知

UIKeyboardWillShowNotification//键盘即将显示

UIKeyboardDidShowNotification//键盘显示完毕

UIKeyboardWillHideNotification//键盘即将隐藏

UIKeyboardDidHideNotification//键盘隐藏完毕

UIKeyboardWillChangeFrameNotification//键盘的位置尺寸即将发生改变

UIKeyboardDidChangeFrameNotification//键盘的位置尺寸改变完毕

系统发出键盘通知时,会附带一下跟键盘有关的额外信息(字典),字典常见的key如下:

UIKeyboardFrameBeginUserInfoKey//键盘刚开始的frame

UIKeyboardFrameEndUserInfoKey//键盘最终的frame(动画执行完毕后)

UIKeyboardAnimationDurationUserInfoKey//键盘动画的时间

UIKeyboardAnimationCurveUserInfoKey//键盘动画的执行节奏(快慢)

UIKeyboardAnimationCurveUserInfoKey = 7; //动画执行的节奏

UIKeyboardAnimationDurationUserInfoKey = "0.25";键盘弹出/隐藏的动画所需要的时间

UIKeyboardBoundsUserInfoKey = "NSRect: {{0, 0}, {320, 216}}”;//键盘的bounds

UIKeyboardCenterBeginUserInfoKey = "NSPoint: {160, 588}”;//键盘准备弹出时的X,Y的中心坐标

UIKeyboardCenterEndUserInfoKey = "NSPoint: {160, 372}”;//键盘弹出后的X,Y的中心坐标

//键盘弹出刚开始的那一刻的frame

UIKeyboardFrameBeginUserInfoKey = "NSRect: {{0, 480}, {320, 216}}";

//弹出完毕的时候，键盘的frame

UIKeyboardFrameEndUserInfoKey = "NSRect: {{0, 264}, {320, 216}}";

//键盘退出的frame

//键盘刚要退出那一刻的frame

UIKeyboardFrameBeginUserInfoKey = "NSRect: {{0, 264}, {320, 216}}";

//键盘退出完毕那一刻的frame

UIKeyboardFrameEndUserInfoKey = "NSRect: {{0, 480}, {320, 216}}";

以下是swift:

extension NSNotification.Name {

public static let UIWindowDidBecomeVisible: NSNotification.Name

public static let UIWindowDidBecomeHidden: NSNotification.Name // nil

public static let UIWindowDidBecomeKey: NSNotification.Name // nil

public static let UIWindowDidResignKey: NSNotification.Name // nil

public static let UIKeyboardWillShow: NSNotification.Name

public static let UIKeyboardDidShow: NSNotification.Name

public static let UIKeyboardWillHide: NSNotification.Name

public static let UIKeyboardDidHide: NSNotification.Name

@available(iOS 5.0, *)

public static let UIKeyboardWillChangeFrame: NSNotification.Name

@available(iOS 5.0, *)

public static let UIKeyboardDidChangeFrame: NSNotification.Name