Swift中通知中心(NotificationCenter)的使用示例

  /// 通知名
  let notificationName = "XMNotification"
  /// 自定义通知
  NotificationCenter.default.addObserver(self, selector: #selector(notificationAction), name: NSNotification.Name(rawValue: notificationName), object: nil)

 /// 接受到通知后的方法回调
 @objc private func notificationAction(noti: Notification) {
  /// 获取键盘的位置/高度/时间间隔...
  print(noti)
 }

 /// 析构函数.类似于OC的 dealloc
 deinit {
  /// 移除通知
  NotificationCenter.default.removeObserver(self)
 }

 /// 发送简单数据
 NotificationCenter.default.post(name: NSNotification.Name.init(rawValue: "XMNotification"), object: "Hello 2017")

 /// 发送额外数据
 let info = ["name":"Eric","age":21] as [String : Any]
 NotificationCenter.default.post(name: NSNotification.Name.init(rawValue: "XMNotification"), object: "GoodBye 2016", userInfo: info)

  /// 通知中心监听键盘的变化
  #selector(notificationAction), name: NSNotification.Name.UIKeyboardWillChangeFrame, object: nil)

  public static let UIKeyboardWillShow: NSNotification.Name
  /// 键盘显示完毕
  public static let UIKeyboardDidShow: NSNotification.Name
  /// 键盘将要隐藏
  public static let UIKeyboardWillHide: NSNotification.Name
  /// 键盘隐藏完毕
  public static let UIKeyboardDidHide: NSNotification.Name
  /// 键盘将要改变自身的frame
  public static let UIKeyboardWillChangeFrame: NSNotification.Name
  /// 键盘frame改变完成
  public static let UIKeyboardDidChangeFrame: NSNotification.Name