SwiftUI Binding Test for Button And Picker - swiftui

Question

I would like to make a test with SwiftUI binding.
Aim was changing Picker selection with a button and with an other Picker.
In following code ContentView2's Picker selection will be changed with button in ContentView and Picker in ContentView1.
Button can change ContentView2 picker selection but ContentView1 Picker does not.
I can not find the reason.
You can copy paste code to test.
import SwiftUI
struct ContentView: View {
#State private var index1 = 0
#State private var index2 = 1
var body: some View {
GeometryReader { mainView in
HStack {
Button(action: {
if index2 == 0 {
index2 = 1
} else {
index2 = 0
}
}) {
Text("Button")
}
ContentView1(pickerIndex: $index1)
ContentView2(pickerIndex: $index2)
}
}
}
}
struct ContentView1: View {
#State var pickerData = ["Data1", "Data2"]
#Binding var pickerIndex: Int
#State var pickerIndex2 = 0
var customLabel0: some View{
HStack {
VStack(spacing: 10) {
Text("Picker One")
.foregroundColor(.black)
Text(pickerData[pickerIndex])
.multilineTextAlignment(.center)
}
.foregroundColor(.white)
}
.frame(width: (UIScreen.main.bounds.width - (2.5 * 8 )) * 0.6 * 0.5, height: 100)
.background(Color.gray)
.cornerRadius(5)
}
#State private var testIndex = 1
var body: some View {
Menu {
Picker("", selection: self.$pickerIndex) {
ForEach(0..<pickerData.count, id: \.self) {index in
Text(pickerData[index])
}
}
} label: {
customLabel0
}
.onChange(of: pickerIndex, perform: {_ in
ContentView2(pickerIndex: $pickerIndex)
})
}
}
struct ContentView2: View {
#State var pickerData = ["Data1", "Data2"]
#Binding var pickerIndex: Int
var customLabel0: some View{
HStack {
VStack(spacing: 10) {
Text("Picker Two")
.foregroundColor(.black)
Text(pickerData[pickerIndex])
.multilineTextAlignment(.center)
}
.foregroundColor(.white)
}
.frame(width: (UIScreen.main.bounds.width - (2.5 * 8 )) * 0.6 * 0.5, height: 100)
.background(Color.gray)
.cornerRadius(5)
}
var body: some View {
Menu {
Picker("", selection: $pickerIndex) {
ForEach(0..<pickerData.count, id: \.self) {index in
Text(pickerData[index])
}
}
} label: {
customLabel0
}
.onChange(of: pickerIndex, perform: {_ in
})
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}