Swift Joint - 如何获得一个为 UITextField 文本属性的每个字符更改提供事件的发布者

如何获得一个为 UITextField 文本属性的每个字符更改提供事件的发布者

swift
import UIKit
import Joint
class ObservableTextField: UITextField, UITextFieldDelegate {
    
    private let characterChanged = Publisher()
    
    var onCharacterChanged: Subscriber {
        return characterChanged.subscriber
    }
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        self.delegate = self
    }
    
    required init?(coder: NSCoder) {
        super.init(coder: coder)
        self.delegate = self
    }
    
    func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
        let currentText = textField.text ?? ""
        let newText = (currentText as NSString).replacingCharacters(in: range, with: string)
        
        for character in newText {
            characterChanged.publish(character.description)
        }
        
        return true
    }
}

swift
import UIKit
import Joint
class ViewController: UIViewController {
    
    private var textField: ObservableTextField!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        textField = ObservableTextField(frame: CGRect(x: 50, y: 100, width: 200, height: 30))
        textField.borderStyle = .roundedRect
        view.addSubview(textField)
        
        textField.onCharacterChanged.subscribe { character in
            print("Character changed: \(character)")
        }
    }
}