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

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
    }

其他回答

对于那些正在寻找可重用函数的人,我做了一个负责JSON加载的类。

import Foundation

class JSONLoader {
    static func load<T: Decodable>(resource: String, type: T.Type) -> T {
        guard let file = Bundle.main.url(forResource: resource, withExtension: nil) else {
            fatalError("Couldn't find \(resource) in main bundle.")
        }
        let data: Data
        do {
            data = try Data(contentsOf: file)
        } catch {
            fatalError("Couldn't load \(resource) from main bundle:\n\(error)")
        }
        do {
            return try JSONDecoder().decode(type, from: data)
        } catch {
            fatalError("Couldn't parse \(resource) as \(T.self):\n\(error)")
        }
    }
    
    static func load<T: Decodable>(resource: String) -> T {
        load(resource: resource, type: T.self)
    }
}
// Usage:
let employee1 = JSONLoader.load("employee.json", Employee.self)
let employee2: Employee = JSONLoader.load("employee.json")

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。

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 4.1更新了Xcode 9.2

if let filePath = Bundle.main.path(forResource: "fileName", ofType: "json"), let data = NSData(contentsOfFile: filePath) {

     do {
      let json = try JSONSerialization.jsonObject(with: data as Data, options: JSONSerialization.ReadingOptions.allowFragments)        
        }
     catch {
                //Handle error
           }
 }