Realm Swift返回所有nil值的对象

Question

我使用ObjectMapper将JSON对象解析为Realm.

我的班级旅行看起来像这样:

class Trip: Object, Mappable {
    dynamic var Id : String? = nil
    dynamic var CreatedOn : String? = nil
    dynamic var LastModified : String? = nil

    required convenience init?(_ map: Map) {
        self.init()
    }

    func mapping(map: Map) {
        Id <- map["Id"];
        CreatedOn <- map["CreatedOn"];
        LastModified <- map["LastModified"];
    }
}

我正在使用Alamofire调用Web服务请求:

Alamofire.request(.GET, path, headers: ["Token" : auth_token]).responseJSON { response in

    let dict : NSDictionary? = response.result.value as? NSDictionary

    let test = Mapper<Trip>().map(dict!)
    let realm = try! Realm()
    realm.beginWrite()
    realm.add(test!)
    try! realm.commitWrite()

    let alltrips : Results<Trip> = realm.objects(Trip)
    let firstTrip = alltrips.first
}

在上面的代码中,当我打印测试时,我得到:

(AwesomeApp.Trip?) test = 0x0000000154e8f0d0 {
  RealmSwift.Object = {
    Realm.RLMObjectBase = {
      ObjectiveC.NSObject = {}
    }
  }
  Id = "47d86d34-b6f2-4a9f-9e31-30c81a915492"
  CreatedOn = "2016-01-20T23:39:41.995Z"
  LastModified = "2016-01-20T23:44:39.363Z"
}

当我打印,firstTrip,我明白了

(AwesomeApp.Trip?) firstTrip = 0x0000000154f1f370 {
  RealmSwift.Object = {
    Realm.RLMObjectBase = {
      ObjectiveC.NSObject = {}
    }
  }
  Id = nil
  CreatedOn = nil
  LastModified = nil
}

我使用了Realm Browser,看起来这些值已正确写入数据库.但是,读取值将返回具有所有nil值的trip对象.为什么是这样 ？

编辑:我打印allTrips使用print (allTrips),打印出来:

Results<Trip> (
    [0] Trip {
        Id = 47d86d34-b6f2-4a9f-9e31-30c81a915492;
        CreatedOn = 2016-01-20T23:39:41.995Z;
        LastModified = 2016-01-20T23:44:39.363Z;
    }
 )

Answer 1

Realm 子类的实例变量Object仅用于尚未添加到 Realm 的对象。将对象添加到 Realm 后，或者对于从 Realm 检索对象时，对象 getter 和 setter 直接从 Realm 访问数据，而不使用实例变量。这就是实例变量没有您期望的值的原因。