使用InputAccessoryView键盘输入时滞

Question

我通过inputAccessoryView实现键入并拥有键盘。我的问题是，当我键入文字时，会稍有延迟，当我写“你好”时，每个字母都不会与​​我实际打相应字母时同步。每个字母的显示方式存在滞后。任何有关解决方案的想法都将不胜感激...下面是一些实现代码供参考...

protocol ChatInputAccessoryViewDelegate {
    func didSend(for message: String)
}

class ChatInputTextView: UITextView {
    fileprivate let placeholderLabel: UILabel = {
        let label = UILabel()
        label.text = "Enter Message"
        label.textColor = UIColor.lightGray
        return label
    }()

    func showPlaceholderLabel() {
        placeholderLabel.isHidden = false
    }

    override init(frame: CGRect, textContainer: NSTextContainer?) {
        super.init(frame: frame, textContainer: textContainer)

        NotificationCenter.default.addObserver(self, selector: #selector(handleTextChange), name:  UITextView.textDidChangeNotification, object: nil)

        addSubview(placeholderLabel)
        placeholderLabel.anchor(top: topAnchor, left: leftAnchor, bottom: bottomAnchor, right: rightAnchor, paddingTop: 8, paddingLeft: 8, paddingBottom: 0, paddingRight: 0, width: 0, height: 0)
    }

    @objc func handleTextChange() {
        placeholderLabel.isHidden = !self.text.isEmpty
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init coder has not been implemented")
    }
}

class ChatInputAccessoryView: UIView {

var delegate: ChatInputAccessoryViewDelegate?

func clearTextView() {
    chatTextView.text = nil
    chatTextView.showPlaceholderLabel()
}

let chatTextView: ChatInputTextView = {
    let tv = ChatInputTextView()        
    tv.returnKeyType = UIReturnKeyType.send
    tv.font = UIFont(name: "OpenSans-Regular", size: 14)
    tv.isScrollEnabled = false
    return tv
}()

let sendButton: UIButton = {
    let sb = UIButton(type: .custom)
    sb.setImage(#imageLiteral(resourceName: "chatroom_send_icon"), for: .normal)
    sb.addTarget(self, action: #selector(handleSend), for: .touchUpInside)
    return sb
}()

override init(frame: CGRect) {
    super.init(frame: frame)
    backgroundColor = .white
    autoresizingMask = .flexibleHeight

    addSubview(sendButton)
    sendButton.anchor(top: topAnchor, left: nil, bottom: nil, right: rightAnchor, paddingTop: 0, paddingLeft: 0, paddingBottom: 0, paddingRight: 12, width: 50, height: 50)

    addSubview(chatTextView)
    chatTextView.anchor(top: topAnchor, left: leftAnchor, bottom: safeAreaLayoutGuide.bottomAnchor, right: sendButton.leftAnchor, paddingTop: 8, paddingLeft: 8, paddingBottom: 8, paddingRight: 0, width: 0, height: 0)

    setupLineSeparatorView()
}

required init?(coder aDecoder: NSCoder) {
    fatalError("init(coder:) has not been implemented")
}

override var intrinsicContentSize: CGSize {
    return .zero
}

fileprivate func setupLineSeparatorView() {
    let lineSeparatorView = UIView()
    lineSeparatorView.backgroundColor = UIColor(red: 230/255, green: 230/255, blue: 230/255, alpha: 1)
    addSubview(lineSeparatorView)
    lineSeparatorView.anchor(top: topAnchor, left: leftAnchor, bottom: nil, right: rightAnchor, paddingTop: 0, paddingLeft: 0, paddingBottom: 0, paddingRight: 0, width: 0, height: 0.5)
}

@objc func handleSend() {
    guard let message = chatTextView.text else { return }        
    delegate?.didSend(for: message)
}
}

func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool {
    if(text == "\n") {
        didSend(for: textView.text)
        return false
    } else {
        return true
    }
}