it's really a simple demo here, when I use NavigationLink destination, go to ContentView3(),i show a custom alert, when it show up, the navigation back button still work.what can I do, when my alert show , and set the back button clickable to false?(the alert must be a custom one, cannot use system .alert) import SwiftUI struct ContentView: View { @State var isActive : Bool = false var body: some View { NavigationView { NavigationLink( destination: ContentView2(rootIsActive: self.$isActive), isActive: self.$isActive ) { Text("Hello, World!") } .isDetailLink(false) .navigationBarTitle("Root") }.navigationViewStyle(.stack) } } struct ContentView2: View { @Binding var rootIsActive : Bool var body: some View { NavigationLink(destination: ContentView3(shouldPopToRootView: self.$rootIsActive)) { Text("Hello, World #2!") } .isDetailLink(false) .navigationBarTitle("Two") } } struct ContentView3: View { @Binding var shouldPopToRootView : Bool @State var showTip = false var body: some View { ZStack { VStack { Text("Hello, World #3!") Button (action: { self.shouldPopToRootView = false } ) { Text("Pop to root") } Button (action: { self.showTip.toggle() } ) { Text("show tip") } } // when alert show up, the back button still work, what can I do stop it? let the back button clickable to false? if showTip { TipAlert(isPresented: $showTip, tip: "123445", negative: "", positive: "OK") { } } } .navigationBarTitle("Three") } } struct ContentView_Previews: PreviewProvider { static var previews: some View { ContentView() } } struct TipAlert: View { @Binding var isPresented: Bool let tip: String let negative: String let positive: String let action: (() -> Void) var body: some View { ZStack { Color.gray.edgesIgnoringSafeArea(.all).opacity(0.75) VStack(spacing: 10) { Text(tip) .font(.system(size: kFrontSize_18)) .foregroundColor(.black) HStack (alignment: .center, spacing: 20){ Spacer() if !negative.isEmpty { Button { isPresented.toggle() } label: { Text(negative) .font(.system(size: kFrontSize_15)) .padding(.horizontal, 12) .padding(.vertical, 8) .frame(minWidth: 55) .foregroundColor(.white) .clipShape(RoundedRectangle(cornerRadius: 5)) } } Button { action() isPresented.toggle() } label: { Text(positive) .font(.system(size: kFrontSize_15)) .padding(.horizontal, 12) .padding(.vertical, 8) .frame(minWidth: 55) .foregroundColor(.white) .clipShape(RoundedRectangle(cornerRadius: 5)) } Spacer() } } .padding(10) .background(.white) .frame( width: 340 ) .cornerRadius(5) } } }