在Scrollview中时，UIViewControllerRepresentable不接收焦点更新

Question

我有一个SwiftUI UIViewControllerRepresentable，它已嵌入到ScrollView中（见下文）

import SwiftUI

struct ContactView: View {
    @State private var text = ""
    var body: some View {
        ScrollView{
            TextFieldView(text: $text, dismissKeyboardCallback: nil)
        }
    }
}

当我点击TextField时，什么也没有发生。如果将父ScrollView替换为VStack，则TextFieldRepresentable可以照常接收焦点（出现软键盘，并且可以输入数据）。这是一个错误，还是我做错了什么？如果对UIViewControllerRepresentable有所帮助，则包括在下面：

import SwiftUI

struct TextFieldView: View {
    var text: Binding<String>
    var onDismissKeyboard: (() -> Void)?

    var body: some View {
        TextFieldRepresentable(text: text, dismissKeyboardCallback: self.onDismissKeyboard)
            .frame(height: 32, alignment: .leading)
    }
}

struct TextFieldRepresentable: UIViewControllerRepresentable {
    let dismissKeyboardCallback: (() -> Void)?
    let viewController: TextFieldViewController

    init (text: Binding<String>, dismissKeyboardCallback: (() -> Void)?) {
        self.dismissKeyboardCallback = dismissKeyboardCallback
        self.viewController = TextFieldViewController(text: text, onDismiss: dismissKeyboardCallback)
    }

    func makeUIViewController(context: Context) -> UIViewController {
        return viewController
    }

    func updateUIViewController(_ viewController: UIViewController, context: Context) {}
}

还有TextFieldViewController本身：

class TextFieldViewController: UIViewController, UITextFieldDelegate {
    let text: Binding<String>?
    let onDismiss: (() -> Void)?

    init (text: Binding<String>, onDismiss: (() -> Void)?) {
        self.text = text
        self.onDismiss = onDismiss
        super.init( nibName: "TextField", bundle: Bundle.main)
    }

    required init?(coder: NSCoder) {
        self.text = nil
        self.onDismiss = nil
        super.init(coder: coder)
    }

    fileprivate func getTextField() -> UITextField? {
        return view.subviews.first as? UITextField
    }

    override func viewDidLoad() {
        let textField = self.getTextField()
        textField?.delegate = self

        let toolbar = UIToolbar(frame: CGRect(x: 0, y: 0, width: UIScreen.main.bounds.width, height: 50))
        toolbar.barStyle = UIBarStyle.default
        toolbar.items = [UIBarButtonItem(title: "Done", style: UIBarButtonItem.Style.done, target: self, action: #selector(self.onSet))]
        textField?.inputAccessoryView = toolbar
    }

    @objc private func onSet() {
        let textField = self.getTextField()
        textField?.resignFirstResponder()
        self.text?.wrappedValue = textField?.text ?? ""
        self.onDismiss?()
    }
}