How to implement observer in swift-CodePudding

I have the following project which implements an observer in swift in order to pass data between two Views.

Model

import Foundation

class ModelData : ObservableObject {
@Published var number: Int = 1
}

import Foundation
import SwiftUI

struct SliderView: View {

@State private var text = "1"
@State private var isEditing = false
@State private var celsius: Double = 1

@StateObject var modelData = ModelData()

var body: some View {
    VStack {
        
        VStack {
            Text("Number from slider: \(Int(round(celsius)), specifier: "%d")")
            
            Slider(value: $celsius,
                   in: 1...20, step:1.0)
        }.onChange(of: celsius) { _ in
        
            self.text = String(Int(round(celsius)))
            self.modelData.number = Int(round(celsius))
        }
        
        HStack {
            Text("Number")
            Spacer()
            Text(String(text))
        }.padding()
    }
    }
    }

    struct SliderView_Previews: PreviewProvider {
    static var previews: some View {
    SliderView()
    }
    }

import SwiftUI

struct SettingsView: View {
@ObservedObject var modelData = ModelData()

var body: some View {
    ZStack {
        Color.red
        VStack {
        Image("Settings")
            .foregroundColor(.blue)
            .font(.system(size: 100.0))
            Text(String(format: "Number is %d ", modelData.number))
        }
    }
    
}
}

The SettingsView is not updated when data is changed inside SliderView and it remains with the default value of ModelData.

Best regards, Aurelian

CodePudding user response：

In the View with your TabView, declare @StateObject var modelData = ModelData()

and pass it to View1 using .environmentObject(modelData).

In View1 use @EnvironmentObject var modelData: ModelData. Do the same for View2.