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Accepted
koen
Asked: 2024-01-08 03:40:34 +0800 CST

通过取消取消首选项视图时恢复@AppStorage

  • 772

PreferencesView考虑以表格形式呈现的以下内容：

struct PreferencesView: View {
    @Environment(\.dismiss) private var dismiss

    @AppStorage("setting1") var setting1: Bool = true
    @AppStorage("setting2") var setting2: Bool = false
    @AppStorage("setting3") var setting3: Bool = false
    // many more

    var body: some View {
        NavigationView {
            Form {
                Toggle("Setting 1", isOn: $setting1)
                Toggle("Setting 2", isOn: $setting2)
                Toggle("Setting 3", isOn: $setting3)
            }
            .navigationTitle("Preferences")
            .toolbar {
                ToolbarItem(placement: .navigationBarLeading) {
                    Button("Cancel") {
                        reset()

                        dismiss()
                    }
                }
                ToolbarItem(placement: .navigationBarTrailing) {
                    Button("Save") {
                        dismiss()
                    }
                }
            }
        }
    }

    private func reset() {
        // what do I put here?
    }
}

如果用户点击取消，我希望将设置值设置回工作表打开时的值。我可以添加单独的initialSetting1等属性，然后在reset函数中添加setting1 = initialSetting1。但设置很多就变得乏味了。

还有别的办法吗？

swiftui

1 个回答

  1. Best Answer
    • 使用加载当前设置onAppear
    • 使用 local@State绑定到切换开关
    • @State当用户按下“保存”按钮时，将当前值保存到设置。

    像这样：

    struct PreferencesView: View {
    @Environment(\.dismiss) private var dismiss

    @AppStorage("setting1") var setting1: Bool = true
    @AppStorage("setting2") var setting2: Bool = false
    @AppStorage("setting3") var setting3: Bool = false
    
    // Initial value doesn't matter, will be overwritten
    @State var currentSetting1: Bool = false
    @State var currentSetting2: Bool = false
    @State var currentSetting3: Bool = false
    // many more

    var body: some View {
        NavigationView {
            Form {
                // Change internal state, not settings
                Toggle("Setting 1", isOn: $currentSetting1)
                Toggle("Setting 2", isOn: $currentSetting2)
                Toggle("Setting 3", isOn: $currentSetting3)
            }
            .navigationTitle("Preferences")
            .toolbar {
                ToolbarItem(placement: .navigationBarLeading) {
                    Button("Cancel") {
                        // No need to do anything here
                        dismiss()
                    }
                }
                ToolbarItem(placement: .navigationBarTrailing) {
                    Button("Save") {
                        // Save current internal state to settings
                        setting1 = currentSetting1
                        setting2 = currentSetting2
                        setting3 = currentSetting3
                        dismiss()
                    }
                }
            }
            .onAppear() {
                // Load settings
                currentSetting1 = setting1
                currentSetting2 = setting2
                currentSetting3 = setting3
            }
        }
    }
}
    • 1

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