Question

我需要一个外部的键盘管理器类，因为我有许多需要该服务的Viewcontrollers。我编写的代码在物理上位于Viewcontroller中时工作得很完美，但是一旦我通过Keyboard Manager类调用它，我就会得到＆＃34; libc ++ abi.dylib：以NSException类型的未捕获异常终止＆＃34;。

我知道这个错误通常意味着有一些与IBOutlet断开的连接，但在这种情况下我不确定这是如何相关的。

该类基本上告诉viewcontroller中的scrollview调用它向上滚动并使文本字段可见，在编辑完成时恢复状态并在点击scrollview时隐藏键盘。我也尝试使用与KeyboardManagerDelegate相同的方法，结果相同。我也尝试在任何可能的组合中将activeField，vc和scrollView变量更改为弱，但它没有改变任何内容。

这里是KeyboardManager的代码：

import UIKit

class KeyboardManager {
    var activeField: UITextField?
    var vc: UIViewController!
    var scrollView: UIScrollView!

    init(_ vc: UIViewController, _ scrollView: UIScrollView, _ activeField: UITextField?) {
        self.vc = vc
        self.scrollView = scrollView
        self.activeField = activeField
        NotificationCenter.default.addObserver(vc, selector: #selector(keyboardDidShow), name: .UIKeyboardDidShow, object: nil)
        NotificationCenter.default.addObserver(vc, selector: #selector(keyboardWillHide), name: .UIKeyboardWillHide, object: nil)

        let tap = UITapGestureRecognizer(target: vc, action: #selector(hideKeyboard))
        tap.numberOfTouchesRequired = 1
        self.scrollView.addGestureRecognizer(tap)
    }

    @objc func keyboardDidShow(notification: NSNotification) {
        if let activeField = activeField, let keyboardSize = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
            print("Keyboard height is \(keyboardSize.height)")
            let contentInsets = UIEdgeInsets(top: 0.0, left: 0.0, bottom: keyboardSize.height, right: 0.0)
            scrollView.contentInset = contentInsets
            scrollView.scrollIndicatorInsets = contentInsets
            scrollView.scrollRectToVisible(activeField.frame, animated: true)
        }
    }

    @objc func keyboardWillHide(notification: NSNotification) {
        let contentInsets = UIEdgeInsets.zero
        scrollView.contentInset = contentInsets
        scrollView.scrollIndicatorInsets = contentInsets
    }

    @objc func hideKeyboard() {
        activeField?.resignFirstResponder()
    }

}

Viewcontroller中的相关代码在这里：

class ViewController: UIViewController, UITextFieldDelegate {

    weak var activeField: UITextField?
    var keyboardManager: KeyboardManager!
    @IBOutlet weak var scrollView: UIScrollView!
    @IBOutlet weak var textField: UITextField!


override func viewDidLoad() {
        super.viewDidLoad()
        keyboardManager = KeyboardManager(self, scrollView, activeField)
}

    func textFieldDidBeginEditing(_ textField: UITextField) {
        self.activeField = textField
    }

    func textFieldDidEndEditing(_ textField: UITextField) {
        self.activeField = nil
    }
}

提前感谢有关如何使这项工作的任何见解，因为我的项目现在处于暂停状态，直到我能够解决这个问题，如果我要复制和放弃，那将是太多的重复。将此代码粘贴到我拥有的每个ViewController中。

更新：我刚刚在自己的项目中发现了一些我以前没有看到的有趣内容：KeyboardManagerDrama [1731：3465043] 由于未捕获的异常终止应用程序＆＃39; NSInvalidArgumentException＆＃39;，原因：＆＃39 ; - [KeyboardManagerDrama.ViewController keyboardDidShowWithNotification：]：无法识别的选择器发送到实例0x15fe18790＆＃39; 所以我想也许是因为我将观察者设置为vc但是viewcontroller没有选择器功能。如果是这种情况，如何在将查看器功能保持在KeyboardManager中的同时将观察者设置为viewcontroller？

Answer 1

崩溃的原因是您添加了错误的通知观察者。请尝试以下代码。

NotificationCenter.default.addObserver(self, selector: #selector(keyboardDidShow), name: .UIKeyboardDidShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide), name: .UIKeyboardWillHide, object: nil)

let tap = UITapGestureRecognizer(target: self, action: #selector(hideKeyboard))

将vc替换为self。在ViewController

中

您没有方法keyboardDidShow，keyboardWillHide，hideKeyboard。这就是你崩溃的原因

另外，在ViewController中创建activeField时，您应该将textField替换为KeyboardManager，如下所示：

keyboardManager = KeyboardManager(self, scrollView, textField)

Answer 2

代码有两个问题：首先观察者设置在一个视图控制器上，当它应该像@trungduc那样自我设置时说：

NotificationCenter.default.addObserver(self, selector: #selector(keyboardDidShow), name: .UIKeyboardDidShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide), name: .UIKeyboardWillHide, object: nil)

let tap = UITapGestureRecognizer(target: self, action: #selector(hideKeyboard))

其次，在KeyboardManager实例中没有更新activeField属性，因此将其添加到Viewcontroller解决了100％的问题：

weak var activeField: UITextField? { 
    didSet { 
          keyboardManager.activeField = activeField 
    } 
}

Swift：如何将Observer设置为外部类实例，同时将选择器保留在类中？

2 个答案: