需要帮助让 NavigationLink 在 SwiftUI 中工作

Question

我目前正在通过 www.hackingwithswift.com 学习 Swift 和 SwiftUI 我目前正在进行编码练习，无法让我的 ContentView 达到 link 使用 NavigationLink 到不同的 SwiftUI 视图。

如果我用一些随机文本替换我的目的地，就可以了。当我尝试将我的 SwiftUI 视图作为目标插入时，代码就会中断。我看了一个又一个视频，但我不明白为什么我的代码不起作用。下面是我的 ContentView 代码以及 SwiftUI 视图（命名为：UserView.swift）。我认为这与 UserView_Previews 有关，但我不确定。任何 help/ideas/suggestions 将不胜感激！

ContentView 代码

struct ContentView: View {
    @State private var results = [User]()
    
    var body: some View {
        NavigationView {
            List(results, id: \.id) {item in
                NavigationLink(destination: UserView(results: results)) {
                    VStack(alignment: .leading) {
                        Text(item.name)
                            .font(.headline)
                        Text("Age: \(item.age)")
                            .foregroundColor(Color.red)
                    }
                }
            }
        .onAppear(perform: loadData)
        }
    }
    
    func loadData() {
        guard let url = URL(string: "https://www.hackingwithswift.com/samples/friendface.json") else {
            print("Invalid URL")
            return
        }
        
        let request = URLRequest(url: url)
        
        URLSession.shared.dataTask(with: request) { data, response, error in
            if let data = data {
                DispatchQueue.main.async {
                    do {
                        self.results = try JSONDecoder().decode([User].self, from: data)
                    } catch {
                        print(error)
                    }
                }
            }
        }.resume()
    }
}

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

UserView.swift

import SwiftUI

struct UserView: View {
    let results: User
    
    var body: some View {
        ScrollView(.vertical) {
            VStack {
                Text(results.email)
                    .font(.headline)
                Text(results.address)
                
            }
        }
    }
}

struct UserView_Previews: PreviewProvider {
    static let results = User(id: "123", isActive: true, name: "Cody", age: 34, company: "Some Company", email: "Some Email", address: "Some Address", about: "About Me", registered: "Yes", tags: ["1", "2"], friends: [User.Friend(id: "456", name: "Some Friend Name")])
    
    static var previews: some View {
        UserView(results: results)
    }
}

UserFile.swift 这是构建我的用户结构

import Foundation

struct User: Codable, Identifiable {
    let id: String
    let isActive: Bool
    let name: String
    let age: Int
    let company: String
    let email: String
    let address: String
    let about: String
    let registered: String
    let tags: [String]
    let friends: [Friend]
    
    struct Friend: Codable {
        let id: String
        let name: String
    }
}

Answer 1

您的 List 正在遍历 results，即 [User]，因此 item 是一个 User，应该传递给 UserView() 期待单个 User，而不是 Users.

的数组

var body: some View {
    NavigationView {
        List(results, id: \.id) { item in
            NavigationLink(destination: UserView(results: item)) { // here
                VStack(alignment: .leading) {
                    Text(item.name)
                        .font(.headline)
                    Text("Age: \(item.age)")
                        .foregroundColor(Color.red)
                }
            }
        }
    .onAppear(perform: loadData)
    }
}

I think it has something to do with the UserView_Previews, but I am not sure.

User_Previews 只是单元测试数据，允许您在 Xcode 的预览窗格中测试 User View。构建时不使用它。

需要帮助让 NavigationLink 在 SwiftUI 中工作

Need help getting NavigationLink to work in SwiftUI

swift

swiftui

swiftui-navigationlink