将 JSON 转换为自定义对象时出错

Posted 2023-03-16

【中文标题】将 JSON 转换为自定义对象时出错

【英文标题】：Error casting JSON to custom object

【发布时间】：2015-10-09 09:49:42

【问题描述】：

我有一个不为人知的错误。

我尝试使用自定义对象反序列化字典。但它不起作用。

let decodedJson = try! NSJSONSerialization.JSONObjectWithData(data!, options: NSJSONReadingOptions.AllowFragments) as! Dictionary<String, TestCast>

我的对象是（我用objective-c对象进行了测试，但结果相同）

class TestCast: NSObject 

    var ca:String?
    var resultat:String?
    var remuneration:String?
    var delta_ca:String?
    var delta_resultat:String?
    var delta_remuneration:String?

我的 json 是：

"201310": 
    "resultat": 0,
    "delta_resultat": "0.00",
    "delta_remuneration": "0.00",
    "ca": 0,
    "remuneration": 0,
    "delta_ca": "0.00"
,
"201311": 
    "resultat": 0,
    "delta_resultat": "0.00",
    "delta_remuneration": "0.00",
    "ca": 0,
    "remuneration": 0,
    "delta_ca": "0.00"
,
"201312": 
    "resultat": 0,
    "delta_resultat": "0.00",
    "delta_remuneration": "0.00",
    "ca": 0,
    "remuneration": 0,
    "delta_ca": "0.00"
,
"201401": 
    "resultat": 0,
    "delta_resultat": "0.00",
    "delta_remuneration": "0.00",
    "ca": 0,
    "remuneration": 0,
    "delta_ca": "0.00"
,
"201402": 
    "resultat": 0,
    "delta_resultat": "0.00",
    "delta_remuneration": "0.00",
    "ca": 0,
    "remuneration": 0,
    "delta_ca": "0.00"
,
"201403": 
    "resultat": 0,
    "delta_resultat": "0.00",
    "delta_remuneration": "0.00",
    "ca": 0,
    "remuneration": 0,
    "delta_ca": "0.00"
,
"201404": 
    "resultat": 0,
    "delta_resultat": "0.00",
    "delta_remuneration": "0.00",
    "ca": 0,
    "remuneration": 0,
    "delta_ca": "0.00"
,
"201405": 
    "resultat": 0,
    "delta_resultat": "0.00",
    "delta_remuneration": "0.00",
    "ca": 0,
    "remuneration": 0,
    "delta_ca": "0.00"
,
"201406": 
    "resultat": 0,
    "delta_resultat": "0.00",
    "delta_remuneration": "0.00",
    "ca": 0,
    "remuneration": 0,
    "delta_ca": "0.00"
,
"201407": 
    "resultat": 0,
    "delta_resultat": "0.00",
    "delta_remuneration": "0.00",
    "ca": 0,
    "remuneration": 0,
    "delta_ca": "0.00"
,
"201408": 
    "resultat": 0,
    "delta_resultat": "0.00",
    "delta_remuneration": "0.00",
    "ca": 0,
    "remuneration": 0,
    "delta_ca": "0.00"
,
"201409": 
    "resultat": 0,
    "delta_resultat": "0.00",
    "delta_remuneration": "0.00",
    "ca": 0,
    "remuneration": 0,
    "delta_ca": "0.00"
,
"201410": 
    "resultat": 3938.33,
    "delta_resultat": "3,938.33",
    "delta_remuneration": "-2,700.00",
    "ca": 3938.33,
    "remuneration": 2700,
    "delta_ca": "3,938.33"
,
"201411": 
    "resultat": 3938.33,
    "delta_resultat": "0.00",
    "delta_remuneration": "0.00",
    "ca": 3938.33,
    "remuneration": 2700,
    "delta_ca": "0.00"
,
"201412": 
    "resultat": 34211.1,
    "delta_resultat": "30,272.77",
    "delta_remuneration": "0.00",
    "ca": 34211.1,
    "remuneration": 2700,
    "delta_ca": "30,272.77"
,
"201501": 
    "resultat": 7812.89,
    "delta_resultat": "-26,398.21",
    "delta_remuneration": "2,700.00",
    "ca": 13500,
    "remuneration": 0,
    "delta_ca": "-20,711.10"
,
"201502": 
    "resultat": -20195.54,
    "delta_resultat": "-28,008.43",
    "delta_remuneration": "0.00",
    "ca": 5700,
    "remuneration": 0,
    "delta_ca": "-7,800.00"
,
"201503": 
    "resultat": 2379.71,
    "delta_resultat": "22,575.25",
    "delta_remuneration": "0.00",
    "ca": 4650,
    "remuneration": 0,
    "delta_ca": "-1,050.00"
,
"201504": 
    "resultat": 14582.38,
    "delta_resultat": "12,202.67",
    "delta_remuneration": "0.00",
    "ca": 16500,
    "remuneration": 0,
    "delta_ca": "11,850.00"
,
"201505": 
    "resultat": 4568.45,
    "delta_resultat": "-10,013.93",
    "delta_remuneration": "0.00",
    "ca": 9200,
    "remuneration": 0,
    "delta_ca": "-7,300.00"
,
"201506": 
    "resultat": 9941.67,
    "delta_resultat": "5,373.22",
    "delta_remuneration": "-49.60",
    "ca": 12349.67,
    "remuneration": 49.6,
    "delta_ca": "3,149.67"
,
"201507": 
    "resultat": 8138.53,
    "delta_resultat": "-1,803.14",
    "delta_remuneration": "-90.40",
    "ca": 13526.67,
    "remuneration": 140,
    "delta_ca": "1,177.00"
,
"201508": 
    "resultat": 3321.47,
    "delta_resultat": "-4,817.06",
    "delta_remuneration": "140.00",
    "ca": 4500,
    "remuneration": 0,
    "delta_ca": "-9,026.67"
,
"201509": 
    "resultat": -2454.47,
    "delta_resultat": "-5,775.94",
    "delta_remuneration": "-23.00",
    "ca": 0,
    "remuneration": 23,
    "delta_ca": "-4,500.00"

我有一个错误：

无法将“__NSCFDictionary”(0x104f04ef0) 类型的值转换为“Pulse.TestCast”

【问题讨论】：

您需要使用一些映射框架将字典转换为您的对象。你不能只是施放它

【参考方案1】：

将字典数组类型转换为类不会自动使用字典数据创建此类的实例...

你必须为你的类创建一个初始化器，它从你的 JSON 中获取一个字典作为参数来初始化具有正确类型的值。

例子：

class TestCast: NSObject 
    var ca:Int?
    var resultat:Double?
    var remuneration:Int?
    var delta_ca:String?
    var delta_resultat:String?
    var delta_remuneration:String?
    init(dictionary: [String:AnyObject]) 
        self.ca = dictionary["ca"] as? Int
        self.resultat = dictionary["resultat"] as? Double
        self.delta_resultat = dictionary["delta_resultat"] as? String
        self.delta_ca = dictionary["delta_ca"] as? String
        self.remuneration = dictionary["remuneration"] as? Int
        self.delta_remuneration = dictionary["delta_remuneration"] as? String
    


do 
    if let unwrappedData = data, let json = try NSJSONSerialization.JSONObjectWithData(unwrappedData, options: []) as? [String:[String:AnyObject]] 
        let casts = json.map  TestCast(dictionary: $1) 
        // here `casts` is an array of TestCast objects
    
 catch let error as NSError 
    print(error.description)