SwiftUI: Using @binding, achieve two way state change

BidirectionalStateChange.swift

import SwiftUI

struct BadgeView: View {
    @Binding var viewstate: String
    var body: some View {
        VStack {
            Text(viewstate)
                .padding()
            Button("Tap: Child to parent") {
                // Change made by child entity
                self.$viewstate.wrappedValue = "Hello (Child) \(Int.random(in: 0...10))"
            }
        }
    }
}

struct Wrapper: View {
    @State var parentstate: String = "Hello (initial)"

    var body: some View {
        VStack {
            Spacer()
            BadgeView(viewstate: self.$parentstate)
            Spacer()
            Button("Tap: Parent to Child") {
                // Change made by Parent entity
                parentstate = "Hello (Parent) \(Int.random(in: 0...10))"
            }
        }
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        Wrapper()
    }
}