导航标题未显示在 SwiftUI 上

Question

导航标题不起作用。我使用 Swift5.5.2 在预览中没有导航标题的迹象只是一个空白。

struct ContentView: View {
    
    @State private var firstname = ""
    @State private var lastname = ""
    @State private var birthdate = Date()
    @State private var shouldSendNewsletter = false
    
    
    var body: some View {
        NavigationView {
            Form {
                Section(header: Text("Personal Information")) {
                    TextField("First Name", text: $firstname)
                    TextField("Last Name", text: $lastname)
                    DatePicker("Birth Date", selection: $birthdate, displayedComponents: .date)
                    
                    Section(header: Text("Actions")) {
                        Toggle("Send Newsletter", isOn: $shouldSendNewsletter)
                    }//:Actions
                    
                }
            }//:Form
        }//: NAVIGATION VIEW
        .navigationTitle("ABC")
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}

导航标题预览

Answer 1

NavigationView是一个容器，其中包含 ChildView。因此.navigationTitle驻留在NavigationView内部，因此为了更改 navigationTitle 我们必须从 NavigationView 内部调用它，如下所示

NavigationView{
    VStack{
    }
    .navigationTitle("ABC")
}