How to access to a variable in another struct? SWIFTUI

问题

I would like to access to variables in other structs to have a total count.

Example code would demonstrate better:

struct level1: View {

@State var score1 = 5 

}

struct level2: View {

@State var score2 = 7 

}

In another struct, I would like to be able use score1 and score2 variables. The below code doesn't work, but I need something like this.

struct finalScore: View {

@State var totalScore = level1.score1 + level2.score2 

}

回答1:

Rethink it in some different way... like below, single-source trust, model separated - view separated, model changed - view react, this is the way SwiftUI goes.

import SwiftUI
import Combine

class ScoreModel: ObservableObject {
    @Published var score1 = 5
    @Published var score2 = 7
}

struct MainView: View {
    @ObservedObject var vm: ScoreModel = ScoreModel()

    var body: some View {
        VStack {
            level1(vm: vm)
            level2(vm: vm)
            Divider()
            finalScore(vm: vm)
        }
    }
}
struct level1: View {
    @ObservedObject var vm: ScoreModel

    var body: some View {
        Text("\(vm.score1)")
    }
}

struct level2: View {
    @ObservedObject var vm: ScoreModel

    var body: some View {
        Text("\(vm.score2)")
    }
}

struct finalScore: View {
    @ObservedObject var vm: ScoreModel

    var body: some View {
        Text("\(vm.score1 + vm.score2)")
    }
}

回答2:

You would need to use @State & @Binding to accomplish this. Here's a working code that does what you are asking for.

import SwiftUI

struct ContentView: View {

    @State var score1: Int = 5
    @State var score2: Int = 7

    var body: some View {
        VStack {
            HStack {
                FirstView(score1: $score1)
                SecondView(score2: $score2)
                Spacer()
            }
            Divider()
            Text("The total score is \(score1 + score2)")
            Spacer()
        }
        .padding()
    }
}

struct FirstView: View {
    @Binding var score1: Int

    var body: some View {
        Stepper(value: $score1, in: 0...100) {
            Text("\(score1)")
        }
    }
}

struct SecondView: View {
    @Binding var score2: Int

    var body: some View {
        Stepper(value: $score2, in: 0...100) {
            Text("\(score2)")
        }
    }
}

来源：https://stackoverflow.com/questions/60639311/how-to-access-to-a-variable-in-another-struct-swiftui

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variables

swiftui

access