在Swift中将JSON字符串转换为Object的简单方法

Question

我一直在寻找将Swift中一个相当简单的JSON字符串转换为对象类型但无济于事的日子。

这是Web服务调用的代码：

func GetAllBusiness() {

        Alamofire.request(.GET, "http://MyWebService/").responseString { (request, response, string, error) in

                println(string)

        }
}

我有一个快速的结构Business.swift：

struct Business {
    var Id : Int = 0
    var Name = ""
    var Latitude = ""
    var Longitude = ""
    var Address = ""
}

这是我部署的测试服务：

[
  {
    "Id": 1,
    "Name": "A",
    "Latitude": "-35.243256",
    "Longitude": "149.110701",
    "Address": null
  },
  {
    "Id": 2,
    "Name": "B",
    "Latitude": "-35.240592",
    "Longitude": "149.104843",
    "Address": null
  }
  ...
]

如果有人通过这个指导我会很高兴。

谢谢。

Answer 1

这里有一些技巧，以简单的例子开始。

考虑您具有以下JSON Array String（类似于您的）：

 var list:Array<Business> = []

  // left only 2 fields for demo
  struct Business {
    var id : Int = 0
    var name = ""               
 }

 var jsonStringAsArray = "[\n" +
        "{\n" +
        "\"id\":72,\n" +
        "\"name\":\"Batata Cremosa\",\n" +            
        "},\n" +
        "{\n" +
        "\"id\":183,\n" +
        "\"name\":\"Caldeirada de Peixes\",\n" +            
        "},\n" +
        "{\n" +
        "\"id\":76,\n" +
        "\"name\":\"Batata com Cebola e Ervas\",\n" +            
        "},\n" +
        "{\n" +
        "\"id\":56,\n" +
        "\"name\":\"Arroz de forma\",\n" +            
    "}]"


        // convert String to NSData
        var data: NSData = jsonStringAsArray.dataUsingEncoding(NSUTF8StringEncoding)!
        var error: NSError?

        // convert NSData to 'AnyObject'
        let anyObj: AnyObject? = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions(0),
            error: &error)
        println("Error: \(error)")

     // convert 'AnyObject' to Array<Business>
     list = self.parseJson(anyObj!)

     //===============

    func parseJson(anyObj:AnyObject) -> Array<Business>{

        var list:Array<Business> = []

         if  anyObj is Array<AnyObject> {

            var b:Business = Business()

            for json in anyObj as Array<AnyObject>{
             b.name = (json["name"] as AnyObject? as? String) ?? "" // to get rid of null
             b.id  =  (json["id"]  as AnyObject? as? Int) ?? 0

               list.append(b)
            }// for

        } // if

      return list

    }//func

[编辑]

摆脱null更改为：

b.name = (json["name"] as AnyObject? as? String) ?? ""
b.id  =  (json["id"]  as AnyObject? as? Int) ?? 0

另请参阅**[Coalescing Operator](https://developer.apple.com/library/prerelease/mac/documentation/Swift/Conceptual/Swift_Programming_Language/BasicOperators.html#//apple_ref/doc/uid/TP40014097-CH6-XID_124)**
（aka的参考??）

希望它能帮助您解决问题，