在出现错误/消息的情况下，如何在所有ViewModels中显示/重用SwiftUI中的相同视图(警报)？

struct ContentView: View {
    @State private var showAlert = false
    @State private var alertMessage = ""
    
    var body: some View {
        VStack {
            // Your content views here
            
            Button("Show Alert") {
                showAlert = true
                alertMessage = "This is an alert message."
            }
        }
        .alert(isPresented: $showAlert) {
            Alert(title: Text("Alert"), message: Text(alertMessage), dismissButton: .default(Text("OK")))
        }
    }
}

class AlertManager: ObservableObject {
    @Published var showAlert = false
    @Published var alertMessage = ""
    
    static let shared = AlertManager()
    
    private init() {}
}

@main
struct YourApp: App {
    @StateObject private var alertManager = AlertManager.shared
    
    var body: some Scene {
        WindowGroup {
            ContentView()
                .environmentObject(alertManager)
        }
    }
}

class YourViewModel: ObservableObject {
    @EnvironmentObject private var alertManager: AlertManager
    
    func showError() {
        alertManager.showAlert = true
        alertManager.alertMessage = "An error occurred."
    }
}