数组 – Realm对象返回nil(Swift)

我有一个自定义的多边形对象,所以我可以将地图叠加保存到Realm.我能够成功创建这个对象,但是当我想要检索var多边形对象时,它返回nil.当我打印多边形对象时,它会将所有数据打印出来.

这是它打印出来的样本.

Custompolygon {
    name = polygon1;
    id = p1;
    polygon = polygon {
        coordinates = RLMArray <0x7f928ef36230> (
            [0] Coordinate {
                latitude = -36.914167;
                longitude = 174.904722;
            },[1] Coordinate {
                latitude = -36.9325;
                longitude = 174.957222;
            },. . . 
        );
    };
}

我的函数从Realm加载数据

func loadOverlaysFromrealm(){

    do {

        let realm = try Realm()

        let polygons = realm.objects(Custompolygon)

        for p in polygons {

            var coordinates = [CLLocationCoordinate2D]()

            print(p) // !!!!! prints out what is above
            print(p.polygon) // !!!!! Returns nil. 

            if let coordinateList = p.polygon?.coordinates as? List<Coordinate> {

                for coordinate in coordinateList {
                    coordinates.append(CLLocationCoordinate2DMake(coordinate.latitude,coordinate.longitude))
                }
            }
            print(coordinates) // prints "[]"
            let polygon = MKpolygon(coordinates: &coordinates,count: coordinates.count)
            self.map.addOverlay(polygon)

        }

    } catch let error as NSError {
        print(error.localizedDescription)
    }
}

我的课程

class Custompolygon: Object {

    var name:String = ""
    var id:String = ""
    var polygon:polygon? = nil

}

class polygon: Object {
    var coordinates = List<Coordinate>()
}

class Coordinate: Object {
    var latitude:Double = 0.0
    var longitude:Double = 0.0
}

需要使用动态修饰符声明Object子类的String,Double和Object属性,以允许Realm覆盖属性的getter和setter.如果没有这个,Swift编译器将直接访问对象的实例变量,这不会为Realm提供从Realm文件读取或写入数据的任何机会.有关如何声明每种受支持类型的属性的快速概述,请参阅Realm的 model property cheatsheet.