有人能告诉我我做错了什么吗?我已经看过这里的所有问题,就像从这里
How to decode a nested JSON struct with Swift Decodable protocol?一样,我发现了一个看起来正是我需要的东西
Swift 4 Codable decoding json.
{ "success": true,"message": "got the locations!","data": { "LocationList": [ { "LocID": 1,"LocName": "Downtown" },{ "LocID": 2,"LocName": "Uptown" },{ "LocID": 3,"LocName": "Midtown" } ] } } struct Location: Codable { var data: [LocationList] } struct LocationList: Codable { var LocID: Int! var LocName: String! } class ViewController: UIViewController { override func viewDidLoad() { super.viewDidLoad() let url = URL(string: "/getlocationlist") let task = URLSession.shared.dataTask(with: url!) { data,response,error in guard error == nil else { print(error!) return } guard let data = data else { print("Data is empty") return } do { let locList = try JSONDecoder().decode(Location.self,from: data) print(locList) } catch let error { print(error) } } task.resume() }
我得到的错误是:
typeMismatch(Swift.Array,Swift.DecodingError.Context(codingPath:
[],debugDescription: “Expected to decode Array but found a
dictionary instead.”,underlyingError: nil))
检查JSON文本的概述结构:
{ "success": true,"data": { ... } }
“data”的值是JSON对象{…},它不是数组.
和对象的结构:
{ "LocationList": [ ... ] }
该对象有一个单独的条目“LocationList”:[…],它的值是一个数组[…].
您可能还需要一个结构:
struct Location: Codable { var data: LocationData } struct LocationData: Codable { var LocationList: [LocationItem] } struct LocationItem: Codable { var LocID: Int! var LocName: String! }
用于检测…
var jsonText = """ { "success": true,"data": { "LocationList": [ { "LocID": 1,"LocName": "Downtown" },{ "LocID": 2,"LocName": "Uptown" },{ "LocID": 3,"LocName": "Midtown" } ] } } """ let data = jsonText.data(using: .utf8)! do { let locList = try JSONDecoder().decode(Location.self,from: data) print(locList) } catch let error { print(error) }