UIKeyboardWillHideNotification 上无法识别的选择器

Question

我正在尝试在我的 KeyboardScrollController class 中获取键盘通知，但我得到 UIKeyboardWillHideNotification 和 UIKeyboardDidShowNotification 的无法识别的选择器。

这是我的简单实现：

public class KeyboardScrollController
{
    public func subscribeForKeyboardNotifications()
    {
        NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWasShown:", name: UIKeyboardDidShowNotification, object: nil)
        NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillHide:", name: UIKeyboardWillHideNotification, object: nil)
    }

    public func unsubscribeForKeyboardNotifications()
    {
        NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardDidShowNotification, object: nil);
        NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillHideNotification, object: nil);
    }

    //MARK: Keyboard events
    public func keyboardWasShown(notification: NSNotification)
    {

    }

    public func keyboardWillHide(notification: NSNotification)
    {

    }
}

但是每次出现键盘时它都会崩溃并出现以下错误：

*** NSForwarding: warning: object 0x7fdc8d882730 of class 'KeyboardScrollController' does not implement methodSignatureForSelector: -- trouble ahead Unrecognized selector -[KeyboardScrollController keyboardWillHide:]

我试过 Selecor("keyboardWillHide:")，但没有任何区别。

这里有什么问题？我在 Objective-C 中实施了几次，但我无法在 Swift 中使用它。

Answer 1

啊，突然想到，这到底是什么问题。我必须继承 NSObject 才能使其工作：

public class KeyboardScrollController : NSObject
{
    public func subscribeForKeyboardNotifications()
    {
        NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWasShown:", name: UIKeyboardDidShowNotification, object: nil)
        NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillHide:", name: UIKeyboardWillHideNotification, object: nil)
    }

    public func unsubscribeForKeyboardNotifications()
    {
        NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardDidShowNotification, object: nil);
        NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillHideNotification, object: nil);
    }

    //MARK: Keyboard events
    public func keyboardWasShown(notification: NSNotification)
    {

    }

    public func keyboardWillHide(notification: NSNotification)
    {

    }
}

UIKeyboardWillHideNotification 上无法识别的选择器

Unrecognized selector on UIKeyboardWillHideNotification

nsnotificationcenter

ios

swift

ios9