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[英]How do I print a complex Json to the CollectionView using Swift Codable?
[英]How do I parse this nested JSON using Codable with Swift?
我正在嘗試使用 Codable 解析這個 JSON:
{
"users": [
{
"id": 1,
"name": "Allen Carslake",
"userName": "acarslake0",
"profileImage": "https://source.unsplash.com/random/400x400",
"createdDate": "2019-07-08T00:00:00.000+0000"
},
{
"id": 2,
"name": "Revkah Antuk",
"userName": "rantuk1",
"profileImage": "https://source.unsplash.com/random/400x400",
"createdDate": "2019-07-05T00:00:00.000+0000"
},
{
"id": 3,
"name": "Mirna Saffrin",
"userName": "msaffrin2",
"profileImage": "https://source.unsplash.com/random/400x400",
"createdDate": "2019-05-19T00:00:00.000+0000"
},
{
"id": 4,
"name": "Haily Eilers",
"userName": "heilers3",
"profileImage": "https://source.unsplash.com/random/400x400",
"createdDate": "2019-06-28T00:00:00.000+0000"
},
{
"id": 5,
"name": "Oralie Polkinhorn",
"userName": "opolkinhorn4",
"profileImage": "https://source.unsplash.com/random/400x400",
"createdDate": "2019-06-04T00:00:00.000+0000"
}
]
}
我在這里保持 URL 私有,但它在上面返回 JSON。 到目前為止,這是我的代碼:
import UIKit
struct User: Codable {
let id: Int
let name: String
let userName: String
let profileImage: String
let createdDate: String
}
struct Users: Codable {
let users: String
}
let url = URL(string: "")!
URLSession.shared.dataTask(with: url) { data, _, _ in
if let data = data {
let users = try? JSONDecoder().decode([User].self, from: data)
print(users)
}
}.resume()
我需要能夠訪問 User 屬性,但我認為嵌套對我來說很困難。 任何幫助都很棒!! 謝謝!!
首先:始終Catch
DecodingError
並print
它。 它會准確地告訴您出了什么問題。
發生錯誤是因為您忽略了根對象Users
。 如果您decode(Users.self
.
我的建議:
createdDate
解碼為Date
添加適當的日期解碼策略。profileImage
解碼為URL
(免費)。struct Root : Decodable { // `Users` and `User` is too confusing
let users: [User]
}
struct User : Decodable {
let id: Int
let name: String
let userName: String
let profileImage: URL
let createdDate: Date
}
URLSession.shared.dataTask(with: url) { data, _, error in
if let error = error { print(error); return }
do {
let decoder = JSONDecoder()
let dateFormatter = DateFormatter()
dateFormatter.locale = Locale(identifier: "en_US_POSIX")
dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSSZ"
decoder.dateDecodingStrategy = .formatted(dateFormatter)
let result = try decoder.decode(Root.self, from: data!)
for user in result.users {
print(user.userName, user.id, user.createdDate)
}
} catch {
print(error)
}
}.resume()
json 的根是字典而不是數組,您可以編寫根類但它沒有用,因此您需要
URLSession.shared.dataTask(with: url) { data, _, _ in
do {
if let data = data {
let res = try JSONSerialization.jsonObject(with: data) as! [String:Any]
let usersData = try JSONSerialization.data(withJSONObject: res["users"])
let users = try JSONDecoder().decode([User].self, from: usersData)
print(users)
}
}
catch {
print(error)
}
}.resume()
您的Users
結構(我將其重命名為UsersResponse
)應該包含一個[User]
類型的users
屬性。 然后您可以執行以下操作:
struct UsersResponse: Codable {
let users: [User]
}
URLSession.shared.dataTask(with: url) { data, _, _ in
guard let data = data else { return }
if let users = try? JSONDecoder().decode(Users.self, from: data).users {
users.forEach { user in
print("A user called \(user.name) with an id of \(user.id).")
}
}
}.resume()
請嘗試以下代碼。 這對我有用。
型號分類:
struct UsersResponse: Codable {
let users: [User]
}
struct User: Codable {
let id: Int
let name: String
let userName: String
let profileImage: String?
let createdDate: String
}
網絡類:
public enum EndPoints: String {
case prod = "ProdURL"
case test = "testURL"
}
public enum Result<T> {
case success(T)
case failure(Error)
}
final public class Networking: NSObject {
// MARK: - Private functions
private static func getData(url: URL,
completion: @escaping (Data?, URLResponse?, Error?) -> ()) {
URLSession.shared.dataTask(with: url, completionHandler: completion).resume()
}
/// fetchUsersResponse function will fetch the User Response and returns
/// Result<UsersResponse> as completion handler
public static func fetchUsersResponse(shouldFail: Bool = false, completion: @escaping (Result<UsersResponse>) -> Void) {
var urlString: String?
if shouldFail {
urlString = EndPoints.test.rawValue
} else {
urlString = EndPoints.prod.rawValue
}
guard let mainUrlString = urlString, let url = URL(string: mainUrlString) else { return }
Networking.getData(url: url) { (data, response, error) in
if let error = error {
completion(.failure(error))
return
}
guard let data = data, error == nil else { return }
do {
let decoder = JSONDecoder()
//decoder.dateDecodingStrategy = .millisecondsSince1970
decoder.dateDecodingStrategy = .formatted(setDateFormat())
let json = try decoder.decode(UsersResponse.self, from: data)
completion(.success(json))
} catch let error {
completion(.failure(error))
}
}
}
func setDateFormat() -> DateFormatter {
let dateFormat = DateFormatter()
dateFormat.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSSZ"
return dateFormat
}
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