尝试以紧凑模式访问 UITextView 时 iMessage 扩展程序崩溃

下面是我在 iMessage 应用程序中的完整代码。

class MessagesViewController: MSMessagesAppViewController {

@IBOutlet weak var messageView: UITextView!

fileprivate func setupMessageView() {
    messageView.delegate = self

    messageView.layer.cornerRadius = 10
    messageView.layer.borderColor = UIColor.black.cgColor
    messageView.layer.borderWidth = 5

    messageView.text = "Tap to enter a message"
    messageView.textColor = UIColor(red:0.80, green:0.81, blue:0.82, alpha:1.0)
    messageView.textAlignment = .center

    messageView.font = UIFont.systemFont(ofSize: 20)

    messageView.textContainerInset = UIEdgeInsets(top: 10, left: 10, bottom: 10, right: 10)
}

func initialize() {
    setupMessageView()
}

override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
    self.view.endEditing(true)
}

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view.
    Timer.scheduledTimer(timeInterval: 0.5, target: self, selector: #selector(self.initialize), userInfo: nil, repeats: false)
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

// MARK: - Conversation Handling

override func willBecomeActive(with conversation: MSConversation) {
    // Called when the extension is about to move from the inactive to active state.
    // This will happen when the extension is about to present UI.

    // Use this method to configure the extension and restore previously stored state.
}

override func didResignActive(with conversation: MSConversation) {
    // Called when the extension is about to move from the active to inactive state.
    // This will happen when the user dissmises the extension, changes to a different
    // conversation or quits Messages.

    // Use this method to release shared resources, save user data, invalidate timers,
    // and store enough state information to restore your extension to its current state
    // in case it is terminated later.
}

override func didReceive(_ message: MSMessage, conversation: MSConversation) {
    // Called when a message arrives that was generated by another instance of this
    // extension on a remote device.

    // Use this method to trigger UI updates in response to the message.
}

override func didStartSending(_ message: MSMessage, conversation: MSConversation) {
    // Called when the user taps the send button.
}

override func didCancelSending(_ message: MSMessage, conversation: MSConversation) {
    // Called when the user deletes the message without sending it.

    // Use this to clean up state related to the deleted message.
}

override func willTransition(to presentationStyle: MSMessagesAppPresentationStyle) {
    // Called before the extension transitions to a new presentation style.

    // Use this method to prepare for the change in presentation style.
}

override func didTransition(to presentationStyle: MSMessagesAppPresentationStyle) {
    // Called after the extension transitions to a new presentation style.

    // Use this method to finalize any behaviors associated with the change in presentation style.
}

}

extension MessagesViewController: UITextViewDelegate {
func textViewDidBeginEditing(_ textView: UITextView) {
    if textView == messageView {
        requestPresentationStyle(.expanded)
        if textView.textColor == UIColor(red:0.80, green:0.81, blue:0.82, alpha:1.0) {
            textView.text = nil
            textView.textAlignment = .left
            textView.textColor = UIColor.black
            textView.font = UIFont.systemFont(ofSize: 20)
        }
    }
}

func textViewDidEndEditing(_ textView: UITextView) {
    if textView == messageView {
        if textView.text.isEmpty {
            textView.text = "Tap to enter a message"
            textView.textAlignment = .center
            textView.textColor = UIColor(red:0.80, green:0.81, blue:0.82, alpha:1.0)
            textView.font = UIFont.systemFont(ofSize: 20)
        }
    }
}
}

它有一个UITextView，然后我尝试输入数据。我在执行此操作时遇到一个奇怪的问题。

在初始加载时，如果我点击UITextView，调用扩展模式，但键盘不向上滑动。需要再次点击键盘才能向上滑动。

在日志中，我能够发现textViewDidBeginEditing and textViewDidEndEditing第一次点击时会连续调用方法。不知道为什么会这样！？

无论如何，更让我感兴趣的是现在发生的事情。我可以手动将模式更改为压缩模式，然后再更改为扩展模式。如果在扩展模式下，一旦我点击，键盘就会向上滑动。但是，如果我在紧凑模式下点击，应用程序就会崩溃！

这种情况经常发生。在模拟器和真实设备上。我不知道如何解释这种行为。

无论我将模式从紧凑模式更改为扩展模式再返回多少次，我都可以在扩展模式下输入文本。但是，在第一次点击后，在紧凑模式下，这种情况再也不会发生。

有人有这个问题吗？或者你可以复制这个吗？这是苹果的一个错误吗？

如果您需要在用户点击文本字段后更改呈现样式，您可以添加延迟以确保不会与过渡发生冲突。

最初阻止键盘显示可能会更好（您可能需要在 VC 中设置一个 bool 标志以在 textview 委托中打开关闭以启用此功能），调用

  func textViewShouldBeginEditing(_ textView: UITextView) -> Bool {
    if  !shouldShowKeyBoard {
        self.requestPresentationStyle(.expanded)
        return false
    }
    return true

然后在 MSMessagesAppViewController 委托中启用键盘成为第一响应者 `

 override func didTransition(to presentationStyle: MSMessagesAppPresentationStyle) {
    if presentationStyle == .expanded {
       shouldShowKeyBoard = true
       textView.becomeFirstResponder()
    }
}

`

希望这会有所帮助