在SwiftUI文本中显示发布的整数

Question

我对SwiftUI还是很陌生，遇到了以下问题：

我有一个包含一些整数值的模型，如下所示：

class Game: ObservableObject {

    @Published var ownScore:Int = 0
    @Published var opponentScore:Int = 0

    ... some methods
}

我还需要一个视图来显示这些分数，并在这些值中的任何一个发生更改时进行更新。我需要一些类似的方法，但是，由于值是发布的整数，因此这是行不通的。

struct ScoreView: View {
    @EnvironmentObject var game: Game
    @State var displayOpponent: Bool

    var body: some View {
        VStack {
            if displayOpponent {
                Text("Opponent Score")
                Text("Score: \(game.$opponentScore)")
            } else {
                Text("Your Score")
                Text("Score: \(game.$ownScore)")
            }

        }
    }
}

关于如何正确实现此目标的任何想法？

Answer 1

仅用于文本属性，发布时它们将自动更新

struct ScoreView: View {
    @EnvironmentObject var game: Game
    @State var displayOpponent: Bool

    var body: some View {
        VStack {
            if displayOpponent {
                Text("Opponent Score")
                Text("Score: \(game.opponentScore)")   // no $ 
            } else {
                Text("Your Score")
                Text("Score: \(game.ownScore)")        // no $
            }

        }
    }
}

Answer 2

您的Game对象需要实例化为@ObservedObject而不是@EnvironmentObject，除非您将其注入到代码中未显示的环境中，所以...

class Game: ObservableObject {

    @Published var ownScore:Int = 0
    @Published var opponentScore:Int = 0
}

struct ContentView: View {
    @ObservedObject var game = Game()
    @State var displayOpponent: Bool = true

    var body: some View {
        VStack {
            if displayOpponent {
                Text("Opponent Score")
                Text("Score: \(game.opponentScore)")
            } else {
                Text("Your Score")
                Text("Score: \(game.ownScore)")
            }
        }
    }
}

...会工作。另外，您只是呈现已发布变量的值，因此不需要$。