这是我写的最好的代码，它工作得很好，但是文本很小，它使用UIKit。如果你不喜欢它，你必须坚持文本比较逻辑。

import SwiftUI
import UIKit

struct ContentView: View {
@State private var text = ""

var body: some View {
    MyTextView(text: $text)
        .padding()
}
}

struct MyTextView: UIViewRepresentable {
@Binding var text: String

class Coordinator: NSObject, UITextViewDelegate {
    var parent: MyTextView
    
    init(parent: MyTextView) {
        self.parent = parent
    }
    
    func textViewDidChange(_ textView: UITextView) {
        parent.text = textView.text
    }
    
    func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool {
        if text.isEmpty && textView.text.isEmpty {
            print("Delete key pressed")
        }
        return true
    }
}

func makeCoordinator() -> Coordinator {
    Coordinator(parent: self)
}

func makeUIView(context: Context) -> UITextView {
    let textView = UITextView()
    textView.delegate = context.coordinator
    return textView
}

func updateUIView(_ uiView: UITextView, context: Context) {
    uiView.text = text
}
}

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更新：我也做了比较逻辑：

import SwiftUI

struct ContentView: View {

@State private var text = "Hello, World!"
@State private var old = "Hello, World!"

var body: some View {
    TextField("text" , text: $text)
        .onChange(of: text) {
            if text.count <= old.count {
                print("Deleted the letter: \(old.replacingOccurrences(of: text, with: ""))")
            }
            old = text
        }
}
}

型