ios – Unable update the @State variable in SwiftUI

I hava a variable named index that decorated @State, and I want update value when click setting toolbar button.

The toolbar button’s block is executed, but the value of index still is -1.

I debug and check out the value of currentIndex, it still is -1.

import SwiftUI
import SwiftData

struct HomeView: View {
    
    @State var isPresentingAddView = false
    @State var index = -1

    var body: some View {
        NavigationStack() {
            VStack(alignment: .leading) {
                Spacer()
            }
            .navigationTitle(Text("title"))
            .navigationBarTitleDisplayMode(.inline)
            .toolbar {
                ToolbarItem(placement: .topBarTrailing) {
                    Button {
                        index = 1
                        isPresentingAddView = true
                    } label: {
                        Label("setting", systemImage: "plus")
                    }
                }
            }
        }
        .sheet(isPresented: $isPresentingAddView) {
            let currentIndex = index
        }
    }
}

The toolbar button block code is execute before the sheet block code