SwiftUI -计时器不会在0处停止

import SwiftUI
import Combine

struct ContentView: View {
    @State private var timerValue = 10
    private var cancellable: AnyCancellable?

    var body: some View {
        VStack {
            Text("Timer: \(timerValue)")
                .font(.largeTitle)
                .padding()

            Button(action: {
                startTimer()
            }) {
                Text("Start Timer")
                    .font(.title)
                    .padding()
                    .background(Color.blue)
                    .foregroundColor(.white)
                    .cornerRadius(10)
            }
        }
        .onAppear {
            startTimer()
        }
        .onDisappear {
            stopTimer()
        }
    }

    private func startTimer() {
        cancellable = Timer.publish(every: 1, on: .main, in: .common)
            .autoconnect()
            .sink { [weak self] _ in
                guard let self = self else { return }
                if self.timerValue > 0 {
                    self.timerValue -= 1
                } else {
                    self.stopTimer()
                }
            }
    }

    private func stopTimer() {
        cancellable?.cancel()
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}