Swift JSON解析

• swift4 需要在build settings中把swift 3 @objc inference 设置为on

KVCModel

先看一段JSON数据，这是网络返回的数据

{
    "errorCode": "SUCCESS",
    "message": "",
    "data": {
        "dict": {
            "id": 3,
            "text": "equweiyu"
        },
        "list": [{
            "headId": 0,
            "text": "aaa",
        }, {
            "headId": 1,
            "text": "bbb",
        }, {
            "headId": 2,
            "text": "ccc",
        }, ],
        "page": 0
    }
}

经过封装最后使用的效果

// JSON 数据
var json:AnyObject?
//NetDataModel 
let netData = json.flatMap(NetDataModel.init)
//[listModel]
let list = (netData?.data?["list"] as? [AnyObject])?.map(listModel.init)
//DataModel
let model = netData?.data.flatMap(DataModel.init)

1. 封装一个JSON解析基类

使用setValuesForKeysWithDictionary方法解析，很简单

class KVCModel: NSObject {
    override func setValue(value: AnyObject?, forUndefinedKey key: String) {
    }
    override func setValue(value: AnyObject?, forKey key: String) {
        super.setValue(value, forKey: key)
    }
    convenience init(json: [String:AnyObject]?) {
        self.init()
        json.flatMap(self.setValuesForKeysWithDictionary)
    }
    convenience init(obj:AnyObject?) {
        self.init(json: obj as? [String:AnyObject])
    }
}

但是要注意setValuesForKeysWithDictionary 对 Int 不友好 要使用NSNumber代替

2. 创建Model继承于基类

class NetDataModel:KVCModel {
    var errorCode:String?
    var data:AnyObject?
    var message:String?
}
class DataModel: KVCModel {
    var dict:dictModel?
    var list:[listModel]?
    var page:NSNumber?
    
    override func setValue(value: AnyObject?, forKey key: String) {
        switch key {
        case "dict":
            self.dict = value.flatMap(dictModel.init)
        case "list":
            self.list = (value as? [AnyObject])?.map(listModel.init)
        default:
            super.setValue(value, forKey: key)
        }
    }
}
class dictModel: KVCModel {
    var id:NSNumber?
    var text:String?
}
class listModel: KVCModel {
    var headId:NSNumber?
    var text:String?
}

如果Model的属性是KVCModel 或者[KVCModel] 就在 setValue(value: AnyObject?, forKey key: String) 解析

3. 使用

解析NetDataModel:
let netData = json.flatMap(NetDataModel.init)

解析[listModel]:
let list = (netData?.data?["list"] as? [AnyObject])?.map(listModel.init)

解析DataModel:
let model = netData?.data.flatMap(DataModel.init)