SwiftUI 在视图之间共享模型数据答案

【问题标题】：SwiftUI Sharing model data between viewsSwiftUI 在视图之间共享模型数据
【发布时间】：2021-01-16 12:23:41
【问题描述】：

我有这样的结构，我想问你的方法对我来说似乎是错误的。因此，当我想在 1 个视图中使用 2 个模型时，我必须将它放在一个视图中的 foreach 中。这就是我要的。在我想要的其他页面上使用我在用户个人资料中使用的数据。我该怎么做？你们是怎么做到的？

让我举个例子让你更好地理解：

我想在主页上显示我的用户的用户名数据，我应该怎么做？。事实上，在初始化我的模型一次之后，我想在其他视图中使用它。什么是正确的方法。

  import SwiftUI

struct ContentView: View {
    @StateObject var network = ProfileNetwork()
    var body: some View {
        TabView{
            ProfileView().tabItem { Image(systemName: "house") }
            ForEach(self.network.userprofile,id:\.id){a in
                ShopView(profile_model: a)
            }.tabItem { Image(systemName: "house") }
        }
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}


class ProfileNetwork : ObservableObject {
    @Published var userprofile : [UserPRofile] = [UserPRofile(name: "Test", coin: 1, id: "dsa")]
}

struct ProfileView : View {
    @StateObject var network = ProfileNetwork()
    var body: some View {
        ForEach(self.network.userprofile, id:\.id){ i in
            ProfileViewModel(profile_model: i)
        }
    }
}

struct ProfileViewModel : View {
    var profile_model : UserPRofile
    var body: some View {
        Text(self.profile_model.name)
    }
}

struct UserPRofile : Decodable{
    var name : String
    var coin : Int
    var id : String
}

class ShopeNetwork : ObservableObject {
    @Published var shop : [ShopStore] = [ShopStore(id: "sda", image: "dasd", price: 100, name: "sda")]
}

struct ShopView : View {
    @StateObject var network = ShopeNetwork()
    var profile_model : UserPRofile
    var body: some View {
        ForEach(self.network.shop, id:\.id){ c in
            ShopViewModel(shop_model: c, profile_model: profile_model)
        }
    }
}

struct ShopViewModel : View {
    var shop_model : ShopStore
    var profile_model : UserPRofile
    var body: some View {
        Text(profile_model.name)
        Text(self.shop_model.name)
    }
}


struct ShopStore : Decodable {
    var id : String
    var image : String
    var price : Int
    var name : String
}

【问题讨论】：

这里的首页有什么意义？

标签： swift swiftui

【解决方案1】：

一个可能的解决方案是创建一个@EnvironmentObject 并在根级别注入它：

class AppState: ObservableObject {
    @Published var userProfile: UserPRofile?
}

@main
struct TestApp: App {
    @StateObject private var appState = AppState()

    var body: some Scene {
        WindowGroup {
            ContentView()
                .environmentObject(appState)
        }
    }
}

struct ProfileView: View {
    @EnvironmentObject private var appState: AppState // access as an `@EnvironmentObject`
    @StateObject var network = ProfileNetwork()
    var body: some View {
        VStack {
            ForEach(self.network.userprofile, id: \.id) { i in
                ProfileViewModel(profile_model: i)
            }
        }
        .onAppear {
            appState.userProfile = network.userprofile.first // set `userProfile` globally
        }
    }
}

struct ShopView: View {
    @EnvironmentObject private var appState: AppState // use it in any other view
    ...

【讨论】：

【解决方案2】：

Swift 5、iOS 14

将类设为单例，以便轻松共享。

class ProfileNetwork : ObservableObject {
    @Published var userprofile : [UserPRofile] = [UserPRofile(name: "Test", coin: 1, id: "dsa")]
    static var shared = ProfileNetwork()
}

然后用共享句柄引用它。

struct ContentView: View {
  @StateObject var network = ProfileNetwork.shared
  var body: some View {

....
}

struct ProfileView : View {
  @StateObject var network = ProfileNetwork.shared 
  var body: some View {

....
}

【讨论】：