你如何访问 &在 SwiftUI 2.0 中从多个其他视图编辑 @AppStorage 变量? [英] How do you access & edit an @AppStorage var from multiple other views in SwiftUI 2.0?

问题描述

有没有更好的方法来做到这一点?有没有办法访问环境中的UserDefaults??我做了以下事情:

Is there a better way to do this? Is there a way to access the UserDefaults in the environment?? I did the following:

struct ContentView: View {
    @AppStorage("darkMode") var darkMode = false

    var body: some View {
            SubView(darkMode: $darkMode)
        }
    }
}

struct SubView: View {
    @Binding var darkMode: Bool
    var body: some View {
        Text("Dark Mode is \(darkMode == true ? "on" : "off")")
    }
}

推荐答案

通过在不同的视图中使用 @AppStorage，您仍然可以访问相同的 UserDefaults.standard 存储(除非您明确指定suiteName).

By using @AppStorage in different views you still access the same UserDefaults.standard storage (unless you explicitly specify the suiteName).

这意味着您可以直接在子视图中使用 @AppStorage.

Which means you can just use the @AppStorage directly in the subview.

struct ContentView: View {
    @AppStorage("darkMode") var darkMode = DefaultSettings.darkMode

    var body: some View {
        VStack {
            Button("Toggle dark mode") {
                self.darkMode.toggle()
            }
            SubView()
        }
        .colorScheme(darkMode ? .dark : .light)
        .preferredColorScheme(darkMode ? .dark : .light)
    }
}

struct SubView: View {
    @AppStorage("darkMode") var darkMode = DefaultSettings.darkMode

    var body: some View {
        Text("Dark Mode is \(darkMode == true ? "on" : "off")")
    }
}

enum DefaultSettings {
    static let darkMode = false
}

注意:提取默认的 darkMode 值(到 DefaultSettings 枚举)，因此您不会在每个视图中重复 false.

Note: the default darkMode value is extracted (to the DefaultSettings enum) so you don't repeat false in each view.

或者，您可以将 @AppStorage 直接注入 environment.见:

Alternatively you can inject @AppStorage directly to the environment. See:

• 可以在 SwiftUI 的 Environment 中使用 @AppStorage 吗?

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