SwiftUI：如何从ContentView修改AchievementView中可识别对象的isComplete值

要实现从ContentView修改AchievementView中成就的isComplete状态，需要调整数据结构和数据传递方式，具体操作如下：

1. 修改Achievement结构体
   把isComplete从不可变的let改为可变的var，确保状态可以被修改：

struct Achievement: Identifiable {
    let id = UUID()
    let title: String
    let description: String
    var isComplete: Bool // 改为可变属性
}

2. 将成就数据移至ContentView管理
   在ContentView中用@State声明成就数组作为数据源，同时添加控制sheet显示的状态变量：

struct ContentView: View {
    // 父视图统一管理成就数据
    @State private var achievements = [
        Achievement(title: "Done and Done I", description: "delete 1 task", isComplete: false),
        Achievement(title: "Done and Done II", description: "delete 10 tasks", isComplete: false),
        Achievement(title: "Done and Done III", description: "delete 50 tasks", isComplete: false),
        Achievement(title: "Done and Done IV", description: "delete 100 tasks", isComplete: false),
        Achievement(title: "Done and Done V", description: "delete 1000 tasks", isComplete: false),
        Achievement(title: "Busy bee I", description: "add 1 task", isComplete: false),
        Achievement(title: "Busy bee II", description: "add 10 tasks", isComplete: false),
        Achievement(title: "Busy bee III", description: "add 50 tasks", isComplete: false),
        Achievement(title: "Busy bee IV", description: "add 100 tasks", isComplete: false),
        Achievement(title: "Busy bee V", description: "add 1000 tasks", isComplete: false),
        Achievement(title: "Thank you", description: "rate our app", isComplete: false),
        Achievement(title: "Sharing is caring", description: "share your list", isComplete: false),
        Achievement(title: "No place like home", description: "customize taskfairy", isComplete: false)
    ]
    @State private var showAchievementView = false
    
    var body: some View {
        VStack(spacing: 20) {
            // 示例：点击按钮修改指定成就状态
            Button("标记「Done and Done I」为已完成") {
                if let index = achievements.firstIndex(where: { $0.title == "Done and Done I" }) {
                    achievements[index].isComplete.toggle()
                }
            }
            
            // 唤起成就视图
            Button("查看成就") {
                showAchievementView = true
            }
        }
        .sheet(isPresented: $showAchievementView) {
            // 通过Binding传递数据给AchievementView
            AchievementView(achievements: $achievements)
        }
    }
}

3. 调整AchievementView接收绑定数据
   将原来的@State数组改为@Binding，确保视图能响应数据变化：

struct AchievementView: View {
    // 通过Binding接收父视图的成就数据
    @Binding var achievements: [Achievement]
    
    var body: some View {
        List {
            Section(header: Text("已完成")) {
                ForEach($achievements) { $achievement in
                    if achievement.isComplete {
                        HStack {
                            Image(systemName: "trophy.circle.fill")
                                .scaleEffect(1.5)
                                .padding()
                            VStack(alignment: .leading) {
                                Text(achievement.title)
                                Text(achievement.description)
                                    .font(.system(size: 12))
                                    .foregroundColor(.gray)
                            }
                        }
                    }
                }
            }
            Section(header: Text("未完成")) {
                ForEach($achievements) { $achievement in
                    if !achievement.isComplete {
                        HStack {
                            Image(systemName: "trophy.circle")
                                .scaleEffect(1.5)
                                .padding()
                            VStack(alignment: .leading) {
                                Text(achievement.title)
                                Text(achievement.description)
                                    .font(.system(size: 12))
                                    .foregroundColor(.gray)
                            }
                        }
                    }
                }
            }
        }
    }
}

核心逻辑说明 #

• 数据统一由ContentView管理，AchievementView通过@Binding同步数据，确保修改后两边状态实时更新。
• 实际开发中，可以根据用户操作（如删除任务、添加任务的数量）自动触发对应成就的状态变更，替代示例中的按钮触发逻辑。

内容的提问来源于stack exchange，提问作者BurnDownTheWorld