why my logout button can logout but can't switch the view - swift

Question

I have already set a logout button. The function of that button is correct which can actually logout. But there is a problem: when I press the logout button, I can not switch the page to the view I want, which is LoginsignupView. I can't find amything wrong in my code.
I want to know how to make it correctly.
Here is the code about logout
import SwiftUI
struct MainView: View {
#State private var selection = 0
#ObservedObject private var httpClient = HTTPUser()
#State var isin : Bool = true
var body: some View {
if #available(iOS 14.0, *) {
ZStack{
TabView(selection: $selection){
profile1View()
.tag(0)
.navigationBarBackButtonHidden(true)
.navigationBarHidden(true)
//List(self.httpClient.user,id: \.id){ user in
profile3()
.tag(1)
.navigationBarBackButtonHidden(true)
.navigationBarHidden(true)
ZStack{
Image("background")
.resizable()
.scaledToFill()
.frame(minWidth: 0, maxWidth: .infinity)
.edgesIgnoringSafeArea(.all)
NavigationLink(
destination: LoginsignupView().navigationBarBackButtonHidden(true)
.navigationBarHidden(true))
{
Text("logout").foregroundColor(.white)
.fontWeight(.bold)
.padding(.vertical)
.frame(width: UIScreen.main.bounds.width - 100)
.background(
LinearGradient(gradient: .init(colors: [Color("Color"),Color("Color1"),Color("Color2")]), startPoint: .leading, endPoint: .trailing)
)
}
}
.tag(2)
.onAppear(perform: httpClient.Logout)
.navigationBarBackButtonHidden(true)
.navigationBarHidden(true)
}
.zIndex(0)
.onAppear{
UITabBar.appearance().barTintColor = .white
}
}
}
if #available(iOS 14.0, *) {
TabBarView(selection: $selection)
.tabViewStyle(PageTabViewStyle(indexDisplayMode: .never))
} else {
// Fallback on earlier versions
}
Divider()
}
}
struct MainView_Previews: PreviewProvider {
static var previews: some View {
MainView()
}
}

Answer 1

If the intent is to push a LoginSignupView once "Logout" is pressed, then you need a NavigationView somewhere in the view hierarchy. NavigationLink itself won't do much.
However, from your code it looks like you perform logout once the last tab is shown. In which case you might also want to bind your existing NavigationLink to a boolean property. For example your tab might look like this:
NavigationView {
.....
ZStack{
Image("background")
.resizable()
.scaledToFill()
.frame(minWidth: 0, maxWidth: .infinity)
.edgesIgnoringSafeArea(.all)
NavigationLink(
destination: LoginsignupView().navigationBarBackButtonHidden(true)
.navigationBarHidden(true), isActive:$showingLogout)
{
Text("logout").foregroundColor(.white)
.fontWeight(.bold)
.padding(.vertical)
.frame(width: UIScreen.main.bounds.width - 100)
.background(
LinearGradient(gradient: .init(colors: [Color("Color"),Color("Color1"),Color("Color2")]), startPoint: .leading, endPoint: .trailing)
)
}
}
.tag(2)
.onAppear(perform: {
httpClient.Logout()
showingLogout = true
})
.navigationBarBackButtonHidden(true)
.navigationBarHidden(true)
}