SwiftUi使用按钮更改视图

Question

我知道有PresentationButton和NavigationButton，以便在最新的SwiftUI中更改视图。但是，我想做一个简单的操作。当用户单击签名按钮时，如果凭据正确，它将签名，但也可以进行签名(在这种情况下，请更改视图(。但是，我无法检查它们在PresentationButton中是否正确，并且无法以普通按钮更改视图。

有其他方法可以做吗？

  @IBAction func signInClicked(_ sender: Any) {
        
        if emailText.text != "" && passwordText.text != "" {
            
            Auth.auth().signIn(withEmail: emailText.text!, password: passwordText.text!) { (userdata, error) in
                if error != nil {
                   //error
                } else {
                   performSegue(withIdentifier: "toFeedActivity", sender: nil)
                }
            }
        } else {
            //error
        }
    }

Answer 1

这是一种方式。

struct AppContentView: View {
    
    @State var signInSuccess = false
    
    var body: some View {
        return Group {
            if signInSuccess {
                AppHome()
            }
            else {
                LoginFormView(signInSuccess: $signInSuccess)
            }
        }
    }
}
struct LoginFormView : View {
    
    @State private var userName: String = ""
    @State private var password: String = ""
    
    @State private var showError = false
    
    @Binding var signInSuccess: Bool
    
    var body: some View {
        VStack {
            HStack {
                Text("User name")
                TextField("type here", text: $userName)
            }.padding()
            
            HStack {
                Text(" Password")
                TextField("type here", text: $password)
                    .textContentType(.password)
            }.padding()
            
            Button(action: {
                // Your auth logic
                if(self.userName == self.password) {
                    self.signInSuccess = true
                }
                else {
                    self.showError = true
                }
                
            }) {
                Text("Sign in")
            }
            
            if showError {
                Text("Incorrect username/password").foregroundColor(Color.red)
            }
        }
    }
}
struct AppHome: View {
    
    var body: some View {
        VStack {
        Text("Hello freaky world!")
        Text("You are signed in.")
        }
    }
}

Answer 2

我在一个应用程序中也有同样的需求，我找到了一个解决方案...

基本上，您需要在导航视图中插入主视图，然后在视图中添加一个隐形navigationLink，创建一个@State var，该@State var在您想推动视图时控制并在登录回调上更改其值...

那是代码：

struct ContentView: View {
    @State var showView = false
    var body: some View {
        NavigationView {
            VStack {
                Button(action: {
                    print("*** Login in progress... ***")
                    DispatchQueue.main.asyncAfter(deadline: .now() + 3) {
                        self.showView = true
                    }
                }) {
                    Text("Push me and go on")
                }
                //MARK: - NAVIGATION LINKS
                NavigationLink(destination: PushedView(), isActive: $showView) {
                    EmptyView()
                }
            }
        }
    }
}

struct PushedView: View {
    var body: some View {
        Text("This is your pushed view...")
            .font(.largeTitle)
            .fontWeight(.heavy)
    }
}

Answer 3

尝试使用状态＆amp;.Sheet

struct ContentView: View {
    @State var showingDetail = false
    var body: some View {
        Button(action: {
            self.showingDetail.toggle()
        }) {
            Text("Show Detail")
        }.sheet(isPresented: $showingDetail) {
            DetailView()
        }
    }
}

Answer 4

您可以使用标签使用导航链接，

这是代码：

首先，声明标签var

@State var tag : Int? = nil

然后创建您的按钮视图：

Button("Log In", action: {
                        Auth.auth().signIn(withEmail: self.email, password: self.password, completion: { (user, error) in
                            if error == nil {
                                self.tag = 1
                                print("success")
                            }else{
                                print(error!.localizedDescription)
                            }
                        })

因此，当登录成功标签将成为1时，标签将成为1时，您的导航链接将被执行

导航链接代码：

NavigationLink(destination: HomeView(), tag: 1, selection: $tag) {
                EmptyView()
                }.disabled(true)

如果您使用的是form uses use .Disabled，因为这里将在表单上看到空视图，并且您不希望用户单击它并转到Homeview。