当fullScreenCover闭包被触发并通过PresentedView（）传递时，我正在创建一个视图模型。当模态视图被解除时，视图模型永远不会被反初始化。当我再次切换视图时，将创建视图模型的另一个示例。为什么当视图的生命周期结束时，swift没有取消可观察对象的初始化？

struct ContentView: View {
    
    @State var isPresented = false
    
    var body: some View {
        Button("Present!") {
            isPresented.toggle()
        }
        
        .fullScreenCover(isPresented: $isPresented) {
            let vm = ViewModel()
            PresentedView(vm: vm)
        }
    }
}

struct PresentedView: View {
    @Environment(\.dismiss) var dismiss
    @ObservedObject var vm: ViewModel
    
    init(vm: ViewModel) {
        self.vm = vm
    }
    
    var body: some View {
        Text("Presented View").onTapGesture {
            dismiss()
        }
    }
}

class ViewModel: ObservableObject {
    init() {
        print("Init")
    }
    
    deinit {
        print("deinit")
    }
}