在Swift中解码复杂的JSON对象

本文介绍了在Swift中解码复杂的JSON对象的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我对开发完全陌生.试图找到解决方案，但他们无济于事.我需要解码下一个JSON数据:

I'm totally new to development. Tried to find solution but they don't help me. I need do decode next JSON data:

{ "page": { "currentPage": 1, "batchSize": 400, "totalItems": "23" }, "items": [ { "id": "b435a598-421c-4812-a3a9-773c47864558", "firstname": "\u041d\u0410\u0422\u0410\u041b\u0406\u042f \u0412\u0406\u041a\u0422\u041e\u0420\u0406\u0412\u041d\u0410", "lastname": "\u0413\u0423\u041d\u042c\u041a\u041e", "placeOfWork": "\u0437\u0430\u0441\u0442\u0443\u043f\u043d\u0438\u043a \u0434\u0438\u0440\u0435\u043a\u0442\u043e\u0440\u0430-\u043d\u0430\u0447\u0430\u043b\u044c\u043d\u0438\u043a \u0432\u0456\u0434\u0434\u0456\u043b\u0443 \u0441\u043e\u0446\u0456\u0430\u043b\u044c\u043d\u043e\u0457 \u0440\u043e\u0431\u043e\u0442\u0438 ", "position": "", "linkPDF": "public.nazk.gov.ua/storage/documents/pdf/b/4/3/5/b435a598-421c-4812-a3a9-773c47864558.pdf" }, ...... ] }

我尝试了以下代码:

struct Declarant: Codable { var id: String var firstname: String var lastname: String var placeOfWork: String var position: String var linkPDF: String enum CodingKeys: String, CodingKey { case id case firstname case lastname case placeOfWork case position case linkPDF } init(from decoder: Decoder) throws { let valueContainer = try decoder.container(keyedBy: CodingKeys.self) self.id = try valueContainer.decode(String.self, forKey: CodingKeys.id) self.firstname = try valueContainer.decode(String.self, forKey: CodingKeys.firstname) self.lastname = try valueContainer.decode(String.self, forKey: CodingKeys.lastname) self.placeOfWork = try valueContainer.decode(String.self, forKey: CodingKeys.placeOfWork) self.position = try valueContainer.decode(String.self, forKey: CodingKeys.position) self.linkPDF = try valueContainer.decode(String.self, forKey: CodingKeys.linkPDF) } } struct DeclarationInfo: Codable { let items: [Declarant] enum CodingKeys: String, CodingKey { case items } init(from decoder: Decoder) throws { let valueContainer = try decoder.container(keyedBy: CodingKeys.self) self.items = [try valueContainer.decode(Declarant.self, forKey: CodingKeys.items)] } } ... let dataTask = URLSession.shared.dataTask(with: url) { (data, response, error) in let jsonDecoder = JSONDecoder() print("Trying to decode data...") if let data = data, let declarationInfo = try? jsonDecoder.decode(DeclarationInfo.self, from: data) { completion(declarationInfo) print(declarationInfo) } else { print("Either no data was returned, or data was not properly decoded.") completion(nil) } }

并获得

要么没有返回数据，要么没有正确解码数据.

Either no data was returned, or data was not properly decoded.

哪里出了错?

推荐答案

self.items = [try valueContainer.decode(Declarant.self, forKey: CodingKeys.items)]

应该是

self.items = try valueContainer.decode( [ Declarant ].self, forKey: CodingKeys.items )

完整代码:

import UIKit struct Declarant: Codable { var id: String var firstname: String var lastname: String var placeOfWork: String var position: String var linkPDF: String } struct DeclarationInfo: Codable { let items: [Declarant] }

let json = """ { \"page\" : { \"currentPage\" : 1 , \"batchSize\" : 400 , \"totalItems\" : "23" } , \"items\" : [ { \"id\" : "b435a598-421c-4812-a3a9-773c47864558 1" , \"firstname\" : "The first name 1" , \"lastname\" : "The last name 1" , \"placeOfWork\" : "The placeofWork 1" , \"position\" : "The position 1" , \"linkPDF\" : "public.nazk.gov.ua/storage/documents/pdf/b/4/3/5/b435a598-421c-4812-a3a9-773c47864558.pdf" } , { \"id\" : "b435a598-421c-4812-a3a9-773c47864558 2" , \"firstname\" : "The first name 2" , \"lastname\" : "The last name 2" , \"placeOfWork\" : "The placeofWork 2" , \"position\" : "The position 2" , \"linkPDF\" : "public.nazk.gov.ua/storage/documents/pdf/b/4/3/5/b435a598-421c-4812-a3a9-773c47864558.pdf" } ] } """

class ViewController: UIViewController { override func viewDidLoad() { super.viewDidLoad() let jsonDecoder = JSONDecoder() print("Trying to decode data...") if let data = json.data(using: .utf8), let declarationInfo = try? jsonDecoder.decode(DeclarationInfo.self, from: data) { print(declarationInfo) } else { print("Either no data was returned, or data was not properly decoded.") } } }

控制台结果

Trying to decode data... DeclarationInfo(items: [Dec.Declarant(id: "b435a598-421c-4812-a3a9-773c47864558 1", firstname: "The first name 1", lastname: "The last name 1", placeOfWork: "The placeofWork 1", position: "The position 1", linkPDF: "public.nazk.gov.ua/storage/documents/pdf/b/4/3/5/b435a598-421c-4812-a3a9-773c47864558.pdf"), Dec.Declarant(id: "b435a598-421c-4812-a3a9-773c47864558 2", firstname: "The first name 2", lastname: "The last name 2", placeOfWork: "The placeofWork 2", position: "The position 2", linkPDF: "public.nazk.gov.ua/storage/documents/pdf/b/4/3/5/b435a598-421c-4812-a3a9-773c47864558.pdf")])