problems in displaying different titles in navigation bar

问题

in my code I have this:

var body: some View {
   NavigationView {
        VStack(spacing: 0) {
           
        
            ScrollView(.vertical, showsIndicators: false) {
            VStack(spacing: 18) {
                ScrollView(.horizontal, showsIndicators: false){
                    HStack(spacing: 20){
                        Text("teste")
                        .frame(height: 180)
                        .frame(width: 330)
                        .background(Color.blue)
                       .cornerRadius(15)
                        Text("teste")
                        .frame(height: 180)
                        .frame(width: 330)
                        .background(Color.green)
                        .cornerRadius(15)
                        Text("teste")
                        .frame(height: 180)
                        .frame(width: 330)
                        .background(Color.pink)
                        .cornerRadius(15)
                     
                    }.padding(.horizontal, 12)
                }
                ForEach(specialtyList, id: \.type){ specialty in
                    
                    NavigationLink (destination: SearchBar(item: specialty)){
                        VStack(spacing: 18) {
            HStack{
                
                Text(specialty.type).foregroundColor(.white)
                specialty.image
                .renderingMode(.original)
                    .resizable()
                    .frame(width: 35, height: 35)
                  
                
               }.frame(minWidth: 0, idealWidth: 350, maxWidth: .infinity)
                .frame(height: 100)
                        }
                  
                    }.padding(.horizontal)
                        .background(specialty.color).cornerRadius(45)
                   
            
                }.padding(.horizontal)
            }
           
            .padding(.top)
            .padding(.bottom)
                                        
            }
            
    }.navigationBarTitle("Buscar")
            
   
        
   }.accentColor(.black)
}

I want that, according to the button that is pressed in ForEach, the tittle of the next view is the name of the button. Now, the name displaying in every button is "Buscar" I've tried to implement, after ForEach and before NavigationLink, a NavigationView, but the hole ForEach disappears. Basically, I want that the Text(specialty.type) that is pressed is the name of the navigation bar back button. Any ideas?

回答1:

Here is a demo of possible approach - the idea is to change navigation bar title on the navigation link activation and reset on back.

Demo prepared & tested with Xcode 12 / iOS 14

struct DemoView: View {
    @State private var barTitle = ""
    @State private var selectedType = ""
    @State private var isActive = false

    let types = ["Type1", "Type2", "Type3"]

    var body: some View {
        NavigationView {
            VStack {
                ForEach(types, id: \.self) { type in
                    Button(type) {
                        self.isActive = true
                        self.selectedType = type
                        self.barTitle = type         // comment for variant 2
                    }
                }
            }
            .background(
                NavigationLink(destination:
                    Text(selectedType)
//                        .onAppear { self.barTitle = self.selectedType } // variant 2
                    , isActive: $isActive) { EmptyView() }
            )
            .navigationBarTitle(barTitle)
            .onAppear {
                self.barTitle = "Buscar"
            }
        }
    }
}

来源：https://stackoverflow.com/questions/63634075/problems-in-displaying-different-titles-in-navigation-bar