Swiftui macOS应用程序的快捷界面：关闭窗口和打开另一窗口时的User@EnvironmentObject

我的应用程序以登录屏幕开始，您必须输入凭据，如果登录成功，当前窗口将关闭，另一个窗口将打开。在新窗口中，我需要一些来自用户模型（登录时使用）的数据来执行对api的其他请求（基本身份验证）

层次结构：ContentView->LoginView（）->MainPageView（）

AppDelegateCode：

let contentView = ContentView()
    let userVM = CreateUserViewModel()

    // Create the window and set the content view. 
    window = NSWindow(
        contentRect: NSRect(x: 0, y: 0, width: 480, height: 300),
        styleMask: [.titled, .closable, .miniaturizable, .resizable, .fullSizeContentView],
        backing: .buffered, defer: false)
    window.center()
    window.setFrameAutosaveName("Main Window")
    window.contentView = NSHostingView(rootView: contentView.environmentObject(userVM))
    window.makeKeyAndOrderFront(nil)

ContentView代码：

struct ContentView: View {
var body: some View {
    LoginView()
}

struct LoginView: View {

@EnvironmentObject var userVM: CreateUserViewModel
//@ObservedObject var userVM: CreateUserViewModel = CreateUserViewModel()
@State private var showSignUpSheet: Bool = false

var body: some View {
    VStack {

        Text("LubeMarker")
            .font(.title)

        HStack {
            Text("Email")
            TextField("", text: self.$userVM.email)
        }
        HStack {
            Text("Pass")
                .padding([.trailing], 4)
            SecureField("", text: self.$userVM.password)
        }

        HStack {
            Button("Login") {

                self.userVM.loginUser()


                DispatchQueue.main.asyncAfter(deadline: .now() + 2) {
                    if self.userVM.loginUserMessage == "Login Successful" {
                        NSApplication.shared.keyWindow?.close()

                        let window = NSWindow(contentRect: NSRect(x: 20, y: 20, width: 480, height: 300), styleMask: [.titled, .closable, .miniaturizable, .resizable, .fullSizeContentView], backing: .buffered, defer: false)
                        window.center()
                        window.setFrameAutosaveName("Primary Window")
                        window.contentView = NSHostingView(rootView: MainPageView().environmentObject(self.userVM))
                        window.makeKeyAndOrderFront(nil)
                    }
                }

            }
            Button("Sign Up") {
                self.showSignUpSheet = true
            }
        }
        Text(userVM.loginUserMessage)
    }
    .padding([.leading, .trailing], 60)
    //.frame(width: 300, height: 200)
    .sheet(isPresented: self.$showSignUpSheet) {
        SignUpView(showSingUpSheet: self.$showSignUpSheet)
    }
}

}

登录视图代码：

struct ContentView: View {
var body: some View {
    LoginView()
}

struct LoginView: View {

@EnvironmentObject var userVM: CreateUserViewModel
//@ObservedObject var userVM: CreateUserViewModel = CreateUserViewModel()
@State private var showSignUpSheet: Bool = false

var body: some View {
    VStack {

        Text("LubeMarker")
            .font(.title)

        HStack {
            Text("Email")
            TextField("", text: self.$userVM.email)
        }
        HStack {
            Text("Pass")
                .padding([.trailing], 4)
            SecureField("", text: self.$userVM.password)
        }

        HStack {
            Button("Login") {

                self.userVM.loginUser()


                DispatchQueue.main.asyncAfter(deadline: .now() + 2) {
                    if self.userVM.loginUserMessage == "Login Successful" {
                        NSApplication.shared.keyWindow?.close()

                        let window = NSWindow(contentRect: NSRect(x: 20, y: 20, width: 480, height: 300), styleMask: [.titled, .closable, .miniaturizable, .resizable, .fullSizeContentView], backing: .buffered, defer: false)
                        window.center()
                        window.setFrameAutosaveName("Primary Window")
                        window.contentView = NSHostingView(rootView: MainPageView().environmentObject(self.userVM))
                        window.makeKeyAndOrderFront(nil)
                    }
                }

            }
            Button("Sign Up") {
                self.showSignUpSheet = true
            }
        }
        Text(userVM.loginUserMessage)
    }
    .padding([.leading, .trailing], 60)
    //.frame(width: 300, height: 200)
    .sheet(isPresented: self.$showSignUpSheet) {
        SignUpView(showSingUpSheet: self.$showSignUpSheet)
    }
}

}

当我想在MainPageView的子视图中使用@EnvironmentObject时，我遇到以下错误：

Thread 1: Fatal error: No ObservableObject of type CreateUserViewModel found. 
A View.environmentObject(_:) for CreateUserViewModel may be missing as an ancestor of this view.

我假设错误是由于LoginView和MainPageView之间没有父子关系，因为我关闭了窗口，并在login button操作块中打开了另一个窗口

---

有没有办法在swiftUI中链接这两个视图？

找到了解决方案。在LoginView中，我用@ObservedObject属性包装器声明了CreateUserViewModel的一个实例，并将其传递给MainPageView，这也需要在CreateUserViewModel类型的MainPageView中添加一个新属性

LoginView：

@ObservedObject var userVM: CreateUserViewModel = CreateUserViewModel()
@State private var showSignUpSheet: Bool = false

var body: some View {

        HStack {
            Button("Login") {

                self.userVM.loginUser()

                DispatchQueue.main.asyncAfter(deadline: .now() + 2) {

                    if self.userVM.loginUserMessage == "Login Successful" {

                        let mainPage = MainPageView(userVM: self.userVM)
                        NSApplication.shared.keyWindow?.close()

                        let window = NSWindow(contentRect: NSRect(x: 20, y: 20, width: 480, height: 300), styleMask: [.titled, .closable, .miniaturizable, .resizable, .fullSizeContentView], backing: .buffered, defer: false)
                        window.center()
                        window.setFrameAutosaveName("Primary Window")
                        window.contentView = NSHostingView(rootView: mainPage)
                        window.makeKeyAndOrderFront(nil)
                    }

主页视图：

struct MainPageView: View {

@State var selectedProduct: ProductTypes?
@State var showAddProductSheet: Bool = false

var userVM: CreateUserViewModel

var body: some View {
    VStack(spacing: 0) {
        HStack {

            Button("Add Product") {
                self.showAddProductSheet = true
            }
            .padding()

            Spacer()

            Text("Hello World")
        }
    }
    .frame(minWidth: 480, minHeight: 300)
    .sheet(isPresented: self.$showAddProductSheet) {
        AddProductView(showAddProductSheet: self.$showAddProductSheet).environmentObject(self.userVM)
    }
}

}

并从MainPageView将userVM作为环境对象传递给其他视图。我觉得只有使用@ObservedObject才能将关闭的窗口与新窗口连接起来

---

如果在这个场景中有办法使用@EnvironmentObject，我仍然很好奇。

找到了一个解决方案。在LoginView中，我用@ObservedObject属性包装器声明了CreateUserViewModel的一个实例，并将其传递给MainPageView，这也需要在CreateUserViewModel类型的MainPageView中添加一个新属性

LoginView：

@ObservedObject var userVM: CreateUserViewModel = CreateUserViewModel()
@State private var showSignUpSheet: Bool = false

var body: some View {

        HStack {
            Button("Login") {

                self.userVM.loginUser()

                DispatchQueue.main.asyncAfter(deadline: .now() + 2) {

                    if self.userVM.loginUserMessage == "Login Successful" {

                        let mainPage = MainPageView(userVM: self.userVM)
                        NSApplication.shared.keyWindow?.close()

                        let window = NSWindow(contentRect: NSRect(x: 20, y: 20, width: 480, height: 300), styleMask: [.titled, .closable, .miniaturizable, .resizable, .fullSizeContentView], backing: .buffered, defer: false)
                        window.center()
                        window.setFrameAutosaveName("Primary Window")
                        window.contentView = NSHostingView(rootView: mainPage)
                        window.makeKeyAndOrderFront(nil)
                    }

主页视图：

struct MainPageView: View {

@State var selectedProduct: ProductTypes?
@State var showAddProductSheet: Bool = false

var userVM: CreateUserViewModel

var body: some View {
    VStack(spacing: 0) {
        HStack {

            Button("Add Product") {
                self.showAddProductSheet = true
            }
            .padding()

            Spacer()

            Text("Hello World")
        }
    }
    .frame(minWidth: 480, minHeight: 300)
    .sheet(isPresented: self.$showAddProductSheet) {
        AddProductView(showAddProductSheet: self.$showAddProductSheet).environmentObject(self.userVM)
    }
}

}

并从MainPageView将userVM作为环境对象传递给其他视图。我觉得只有使用@ObservedObject才能将关闭的窗口与新窗口连接起来

如果有办法在这个场景中使用@EnvironmentObject，我仍然很好奇