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

遵循以下代码:

if let path = NSBundle.mainBundle().pathForResource("test", ofType: "json")
{
    if let jsonData = NSData(contentsOfFile: path, options: .DataReadingMappedIfSafe, error: nil)
    {
        if let jsonResult: NSDictionary = NSJSONSerialization.JSONObjectWithData(jsonData, options: NSJSONReadingOptions.MutableContainers, error: nil) as? NSDictionary
        {
            if let persons : NSArray = jsonResult["person"] as? NSArray
            {
                // Do stuff
            }
        }
     }
}

数组“persons”将包含关键人物的所有数据。遍历获取它。

斯威夫特4.0:

if let path = Bundle.main.path(forResource: "test", ofType: "json") {
    do {
          let data = try Data(contentsOf: URL(fileURLWithPath: path), options: .mappedIfSafe)
          let jsonResult = try JSONSerialization.jsonObject(with: data, options: .mutableLeaves)
          if let jsonResult = jsonResult as? Dictionary<String, AnyObject>, let person = jsonResult["person"] as? [Any] {
                    // do stuff
          }
      } catch {
           // handle error
      }
}

其他回答

我使用下面的代码从FAQ-data中获取JSON。Json文件存在于项目目录中。

我在Xcode 7.3中使用Swift实现。

     func fetchJSONContent() {
            if let path = NSBundle.mainBundle().pathForResource("FAQ-data", ofType: "json") {

                if let jsonData = NSData(contentsOfFile: path) {
                    do {
                        if let jsonResult: NSDictionary = try NSJSONSerialization.JSONObjectWithData(jsonData, options: NSJSONReadingOptions.MutableContainers) as? NSDictionary {

                            if let responseParameter : NSDictionary = jsonResult["responseParameter"] as? NSDictionary {

                                if let response : NSArray = responseParameter["FAQ"] as? NSArray {
                                    responseFAQ = response
                                    print("response FAQ : \(response)")
                                }
                            }
                        }
                    }
                    catch { print("Error while parsing: \(error)") }
                }
            }
        }

override func viewWillAppear(animated: Bool) {
        fetchFAQContent()
    }

JSON文件结构:

{
    "status": "00",
    "msg": "FAQ List ",
    "responseParameter": {
        "FAQ": [
            {                
                "question": “Question No.1 here”,
                "answer": “Answer goes here”,  
                "id": 1
            },
            {                
                "question": “Question No.2 here”,
                "answer": “Answer goes here”,
                "id": 2
            }
            . . .
        ]
    }
}

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
    }

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。

一般的方法可以是这样的:

创建响应类名称字符串的json文件

struct Response: Codable,FileDecodable {
    typealias T = Self
    let names:[Data]
}
protocol FileDecodable{
   associatedtype T:Codable
   static func loadJson() ->T?
}

extension FileDecodable{
    static func loadJson() -> T? {
        let fileName = String(describing: T.self)
        if let url = Bundle.main.url(forResource: fileName, withExtension: "json")     {
            do {
                let data = try Data(contentsOf: url)
                let decoder = JSONDecoder()
                let jsonData = try decoder.decode(T.self, from: data)
                return jsonData
            } catch {
                print("error:\(error)")
            }
        }
        return nil
    }
}

根据Abhishek的回答,对于iOS 8,这将是:

let masterDataUrl: NSURL = NSBundle.mainBundle().URLForResource("masterdata", withExtension: "json")!
let jsonData: NSData = NSData(contentsOfURL: masterDataUrl)!
let jsonResult: NSDictionary = NSJSONSerialization.JSONObjectWithData(jsonData, options: nil, error: nil) as! NSDictionary
var persons : NSArray = jsonResult["person"] as! NSArray