我想添加保存用户所写内容的功能，所以如果他们返回主页或关闭应用程序并重新打开它，他们所写的内容仍然存在。

下面是我正在使用的代码。我在想是不是还需要再加些什么？

struct LandingView: View {
    @State private var oldLandingName: String = ""
    @State private var newLandingName: String = ""
    @State private var isAddingLanding = false
    @State private var landings: [String] = []
    @State private var isEditing = false
    
    var body: some View {
        NavigationView {
            ZStack {
                Color.blue.ignoresSafeArea()
                Circle()
                    .scale(1.7)
                    .foregroundColor(.yellow.opacity(0.60))
                Circle()
                    .scale(1.3)
                    .foregroundColor(.blue.opacity(0.50))
                
                VStack {
                    HStack {
                        Text("Add Your Travels")
                            .bold()
                        Spacer()
                        Button(action: {
                            isAddingLanding = true
                        }) {
                            Image(systemName: "plus")
                                .resizable()
                                .frame(width: 20, height: 20)
                                .foregroundColor(.white)
                        }
                    }
                    .padding(.horizontal)
                    
                    List(landings, id: \.self) { landing in
                        Text(landing).bold()
                            .foregroundColor(.white)
                            .listRowBackground(Color.clear)
                            .listRowSeparatorTint(.blue)
                            .onTapGesture {
                                self.isEditing = true
                                self.oldLandingName = landing
                                self.newLandingName = landing
                            }
                    }
                    .listStyle(.plain)
                }
                
            }
            .navigationBarTitle(Text("Landings!"))
            
            .fullScreenCover(isPresented: $isAddingLanding, onDismiss: {}) {
                VStack {
                    TextField("Where did you go? \(newLandingName)", text: $newLandingName)
                        .textFieldStyle(RoundedBorderTextFieldStyle())
                        .padding()
                    Button("Add") {
                        if !newLandingName.isEmpty {
                            landings.append(newLandingName)
                            newLandingName = ""
                        }
                        isAddingLanding = false
                    }
                    Color.blue.ignoresSafeArea()
                }
            }
            .fullScreenCover(isPresented: $isEditing, onDismiss: {}) {
                VStack {
                    TextField("", text: $newLandingName)
                        .textFieldStyle(RoundedBorderTextFieldStyle())
                        .padding()
                    Button("Update") {
                        if !newLandingName.isEmpty {
                            if let idx = landings.firstIndex(where: { $0 == $oldLandingName.wrappedValue }) {
                                self.landings[idx] = newLandingName
                            }
                        }
                        isEditing = false
                    }
                    Color.blue.ignoresSafeArea()
                }
            }
            
        }
    }
}