Custom NavigationView top bar

Question

I want to create a design similar to the image above. To create the bottom TabView, I used this code:

import SwiftUI

struct ParentTabView: View {

    var body: some View {
    
        TabView {
            HomeView()
                .tabItem {
                    Image(systemName: "star.fill")
                    Text("Home")
                }
            Text("Second Tab")
                .tabItem {
                    Image(systemName: "star.fill")
                    Text("Discover")
                }
            Text("Third Tab")
                .tabItem {
                    Image(systemName: "star.fill")
                    Text("Settings")
                }
        }
    }
}

and the HomeView

struct HomeView: View {
    var body: some View {
        NavigationView {
            Text("Home")
                .navigationBarItems(
                    trailing:
                        Button(action: {
                        }) {
                            Image(systemName: "plus")
                        }
                )
                .navigationTitle("Home")
        }
    }
}

The problem I encounter is with the top navigation bar, as I'm not able to edit the NavigationView to receive other views below the title. I can set the title and add the "plus" button, but not edit the whole top bar.

Can NavigationView be customized in such a way and if not, how can I achieve that result while still keeping the advantages NavigationViews offer, such as NavigationLinks etc.

Answer 1

The NavigationBar provided by Apple is not quite customizable. You might want to create your customized navigation bar for this use case.

Fortunately, I had some time in hand so I created a simple reusable navigation bar that looks like the outcome you wanted, please take a look below.

You have to to hide Apple's navigation bar, and add the custom navigation bar as an overlay to your navigation view (as seen in the image below):

This is the code for the reusable custom navigation view:

enum CustomNavigationBarItem: String, CaseIterable {
    case dashboard = "Dashboard"
    case feed = "Feed"
    case followers = "Followers"
}

struct CustomNavigationBar: View {
    var title: String
    var items: [CustomNavigationBarItem]
    @Binding var selectedItem: CustomNavigationBarItem
    var buttonAction: () -> ()

    var body: some View {
        VStack {
            VStack(spacing: 10) {
                CustomNavigationBarHeader(title: title, buttonAction: buttonAction)
                
                HStack(spacing: 0) {
                    ForEach(items, id: \.self) { item in
                        CustomNavigationBarItemView(text: item.rawValue, isSelected: selectedItem == item)
                            .onTapGesture {
                                selectedItem = item
                            }
                    }
                }
            }
            .background(Color(#colorLiteral(red: 0.1036974415, green: 0.1036974415, blue: 0.1036974415, alpha: 1)).edgesIgnoringSafeArea(.all))
            
            Spacer()
        }
    }
}

struct CustomNavigationBarItemView: View {
    var text: String
    var isSelected: Bool
    
    var body: some View {
        Text(text)
            .foregroundColor(isSelected ? .blue : Color(#colorLiteral(red: 0.501960814, green: 0.501960814, blue: 0.501960814, alpha: 1)))
            .frame(maxWidth: .infinity)
            .padding(.vertical, 10)
            .padding(.horizontal, 6)
            .overlay(
                VStack {
                    Spacer()
                    Color.blue
                        .frame(height: 2)
                        .opacity(isSelected ? 1 : 0)
                        .animation(.default)
                }
            )
    }
}

struct CustomNavigationBarHeader: View {
    var title: String
    var buttonAction: () -> ()
    
    var body: some View {
        HStack {
            Text(title)
                .font(.title)
                .bold()
            
            Spacer()
            Button(action: buttonAction, label: {
                Image(systemName: "plus")
            })
            .font(.headline)
        }
        .padding(.horizontal)
    }
}

HomeView Code:

struct HomeView: View {
    @State private var selectedNavigationBarItem: CustomNavigationBarItem = .dashboard
    @State private var numPlusButtonClicked: Int = 0
    
    var body: some View {
        NavigationView {
            VStack {
                Text("Home")
                    
                switch selectedNavigationBarItem {
                    case .dashboard:
                        Text("Currently Showing: Dashboard") //Use your view here
                    case .feed:
                        Text("Currently Showing: Feed") //Use your view here
                    case .followers:
                        Text("Currently Showing: Followers") //Use your views here
                }
                
                Text("Plus Button Clicked \(numPlusButtonClicked) times.")
            }
        }
        .navigationBarHidden(true)
        .overlay(
            CustomNavigationBar(title: "Home",
                                items: [.dashboard, .feed, .followers],
                                selectedItem: $selectedNavigationBarItem) {
                numPlusButtonClicked += 1 // Code executed when the "+" button gets called
            }
        )
    }
}

Notes:

1. You can add more items to the "CustomNavigationBarItem" enum
2. By no means this is a perfect component, so feel free to modify it to suit your needs :D

Best of luck!

Edit: Added code for HomeView