我真的在努力把一个JSON文件读入Swift,这样我就可以玩它了。我花了2天的时间重新搜索和尝试不同的方法,但没有运气,所以我已经注册了StackOverFlow,看看是否有人能给我指点正确的方向.....

我的JSON文件叫做test。Json,并包含以下内容:

{
  "person":[
     {
       "name": "Bob",
       "age": "16",
       "employed": "No"
     },
     {
       "name": "Vinny",
       "age": "56",
       "employed": "Yes"
     }
  ]
}    

该文件直接存储在文档中,我使用以下代码访问它:

let file = "test.json"
let dirs : String[] = NSSearchPathForDirectoriesInDomains(
                                                          NSSearchpathDirectory.DocumentDirectory,
                                                          NSSearchPathDomainMask.AllDomainMask,
                                                          true) as String[]

if (dirs != nil) {
    let directories: String[] = dirs
    let dir = directories[0]
    let path = dir.stringByAppendingPathComponent(file)
}

var jsonData = NSData(contentsOfFile:path, options: nil, error: nil)
println("jsonData \(jsonData)" // This prints what looks to be JSON encoded data.

var jsonDict = NSJSONSerialization.JSONObjectWithData(jsonData, options: nil, error: nil) as? NSDictionary

println("jsonDict \(jsonDict)") - This prints nil..... 

如果有人能给我一个正确的方向,我可以反序列化JSON文件,并把它放在一个可访问的Swift对象,我会永远感激!

亲切的问候,

Krivvenz。


当前回答

Swift 4:试试我的解决方案:

test.json

{
    "person":[
        {
            "name": "Bob",
            "age": "16",
            "employed": "No"
        },
        {
            "name": "Vinny",
            "age": "56",
            "employed": "Yes"
        }
    ]
}

RequestCodable.swift

import Foundation

struct RequestCodable:Codable {
    let person:[PersonCodable]
}

PersonCodable.swift

import Foundation

struct PersonCodable:Codable {
    let name:String
    let age:String
    let employed:String
}

可解码+ FromJSON.swift

import Foundation

extension Decodable {

    static func fromJSON<T:Decodable>(_ fileName: String, fileExtension: String="json", bundle: Bundle = .main) throws -> T {
        guard let url = bundle.url(forResource: fileName, withExtension: fileExtension) else {
            throw NSError(domain: NSURLErrorDomain, code: NSURLErrorResourceUnavailable)
        }

        let data = try Data(contentsOf: url)

        return try JSONDecoder().decode(T.self, from: data)
    }
}

例子:

let result = RequestCodable.fromJSON("test") as RequestCodable?

result?.person.compactMap({ print($0) }) 

/*
PersonCodable(name: "Bob", age: "16", employed: "No")
PersonCodable(name: "Vinny", age: "56", employed: "Yes")
*/

其他回答

Swiftyjson版本swift 3

func loadJson(fileName: String) -> JSON {

    var dataPath:JSON!

    if let path : String = Bundle.main.path(forResource: fileName, ofType: "json") {
        if let data = NSData(contentsOfFile: path) {
             dataPath = JSON(data: data as Data)
        }
    }
    return dataPath
}

Swift 3.0, Xcode 8, iOS 10

 if let path = Bundle.main.url(forResource: "person", withExtension: "json") {

        do {
            let jsonData = try Data(contentsOf: path, options: .mappedIfSafe)
            do {
                if let jsonResult = try JSONSerialization.jsonObject(with: jsonData, options: JSONSerialization.ReadingOptions(rawValue: 0)) as? NSDictionary {
                    if let personArray = jsonResult.value(forKey: "person") as? NSArray {
                        for (_, element) in personArray.enumerated() {
                            if let element = element as? NSDictionary {
                                let name = element.value(forKey: "name") as! String
                                let age = element.value(forKey: "age") as! String
                                let employed = element.value(forKey: "employed") as! String
                                print("Name: \(name),  age: \(age), employed: \(employed)")
                            }
                        }
                    }
                }
            } catch let error as NSError {
                print("Error: \(error)")
            }
        } catch let error as NSError {
            print("Error: \(error)")
        }
    }

输出:

Name: Bob,  age: 16, employed: No
Name: Vinny,  age: 56, employed: Yes

Swift 4 JSON类与可解码-为那些喜欢类

定义类如下:

class People: Decodable {
  var person: [Person]?

  init(fileName : String){
    // url, data and jsonData should not be nil
    guard let url = Bundle.main.url(forResource: fileName, withExtension: "json") else { return }
    guard let data = try? Data(contentsOf: url) else { return }
    guard let jsonData = try? JSONDecoder().decode(People.self, from: data) else { return }

    // assigns the value to [person]
    person = jsonData.person
  }
}

class Person : Decodable {
  var name: String
  var age: String
  var employed: String
}

用法,非常抽象:

let people = People(fileName: "people")
let personArray = people.person

这允许People类和Person类的方法,如果需要,变量(属性)和方法也可以标记为private。

斯威夫特 5+

用Struct解码jsonData

if let jsonData = readFile(forName: <your file name>) {

do {
                let decodedData = try JSONDecoder().decode(<your struct name>.self, from: jsonData)
                return decodedData.<what you expect>
            } catch { print("JSON decode error") }
}

这将读取文件并返回jsonData

如果你实际上在另一个bundle中(例如test),使用: let bundlePath = Bundle(for: type(of: self))。路径(forResource: name, ofType: "json")

private func readFile(forName name: String) -> Data? {
        do {

            if let bundlePath = Bundle.main.path(forResource: name, ofType: "json"),
                let jsonData = try String(contentsOfFile: bundlePath).data(using: .utf8) {
                return jsonData
            }
        } catch {
            print(error)
        }
        return nil
    }

我浪费了我的时间在定位文件,它位于我的项目与名称Jsondata.json。但是我无法通过代码....找到我的文件

解决方案:确保您的Jsondata。在项目>构建阶段>复制Bundle资源中添加了json文件。否则你将无法获得file和Bundle.main。url(forResource: fileName, witheextension: "json")将总是给你nil。