RealmSwift：如何实现对象？答案

【问题标题】：RealmSwift: How to implement the Object?RealmSwift：如何实现对象？
【发布时间】：2016-10-02 22:45:09
【问题描述】：

我想使用RealmSwift，因为它似乎是一个易于使用的框架并且可以自己处理很多工作。我阅读了documentation 以了解如何使用它。在文档中写道，我只需导入SwiftRealm 并让我的模型从Object 继承。所以我有这个简单的模型，例如：

import Foundation
import ObjectMapper

func ==(lhs: ADDRESS, rhs: ADDRESS) -> Bool {
    return lhs.hashValue == rhs.hashValue;
}

class VADDRESS : Hashable, Mappable {
    private var id: Int64!;
    private var street: String!;
    private var housenumber: String!;
    private var addition: String!;
    private var postalcode: String!;
    private var location: String!;
    private var country: String!;

    init() {
        self.id = -1;
        self.street = "";
        self.housenumber = "";
        self.addition = "";
        self.postalcode = "";
        self.location = "";
        self.country = "";
    }

    init(id: Int64, street: String, housenumber: String, addition: String, postalcode: String, location: String, country: String) {

        self.id = id;
        self.street = street;
        self.housenumber = housenumber;
        self.addition = addition;
        self.postalcode = postalcode;
        self.location = location;
        self.country = country;
    }

    required init?(map: Map) {

    }

    func mapping(map: Map) {
        self.id <- map["id"];
        self.street <- map["street"];
        self.housenumber <- map["housenumber"];
        self.addition <- map["addition"];
        self.postalcode <- map["postalcode"];
        self.location <- map["location"];
        self.country <- map["country"];
    }

    var hashValue: Int {
        get {
            return "\(self.id),\(self.street),\(self.housenumber),\(self.addition),\(self.postalcode),\(self.location),\(self.country)".hashValue;
        }
    }
}

如果我现在添加对象：

import Foundation
import ObjectMapper

func ==(lhs: ADDRESS, rhs: ADDRESS) -> Bool {
    return lhs.hashValue == rhs.hashValue;
}

class VADDRESS : Object, Mappable {
    private var id: Int64!;
    private var street: String!;
    private var housenumber: String!;
    private var addition: String!;
    private var postalcode: String!;
    private var location: String!;
    private var country: String!;

    init() {
        self.id = -1;
        self.street = "";
        self.housenumber = "";
        self.addition = "";
        self.postalcode = "";
        self.location = "";
        self.country = "";
    }

    init(id: Int64, street: String, housenumber: String, addition: String, postalcode: String, location: String, country: String) {

        self.id = id;
        self.street = street;
        self.housenumber = housenumber;
        self.addition = addition;
        self.postalcode = postalcode;
        self.location = location;
        self.country = country;
    }

    required init?(map: Map) {

    }

    func mapping(map: Map) {
        self.id <- map["id"];
        self.street <- map["street"];
        self.housenumber <- map["housenumber"];
        self.addition <- map["addition"];
        self.postalcode <- map["postalcode"];
        self.location <- map["location"];
        self.country <- map["country"];
    }

    var hashValue: Int {
        get {
            return "\(self.id),\(self.street),\(self.housenumber),\(self.addition),\(self.postalcode),\(self.location),\(self.country)".hashValue;
        }
    }
}

我得到错误超过错误。好的，所以首先我必须重写 init() 方法，因为 Object 似乎已经有一个 init() 方法。 hashValue 也是如此。所以我做到了：

import Foundation
import ObjectMapper

func ==(lhs: ADDRESS, rhs: ADDRESS) -> Bool {
    return lhs.hashValue == rhs.hashValue;
}

class VADDRESS : Object, Mappable {
    private var id: Int64!;
    private var street: String!;
    private var housenumber: String!;
    private var addition: String!;
    private var postalcode: String!;
    private var location: String!;
    private var country: String!;

    required init() {
        super.init();

        self.id = -1;
        self.street = "";
        self.housenumber = "";
        self.addition = "";
        self.postalcode = "";
        self.location = "";
        self.country = "";
    }

    init(id: Int64, street: String, housenumber: String, addition: String, postalcode: String, location: String, country: String) {
        self.id = id;
        self.street = street;
        self.housenumber = housenumber;
        self.addition = addition;
        self.postalcode = postalcode;
        self.location = location;
        self.country = country;
    }

    required init?(map: Map) {

    }
    // Here is the ERROR appearing!
    func mapping(map: Map) {
        self.id <- map["id"];
        self.street <- map["street"];
        self.housenumber <- map["housenumber"];
        self.addition <- map["addition"];
        self.postalcode <- map["postalcode"];
        self.location <- map["location"];
        self.country <- map["country"];
    }

    override var hashValue: Int {
        get {
            return "\(self.id),\(self.street),\(self.housenumber),\(self.addition),\(self.postalcode),\(self.location),\(self.country)".hashValue;
        }
    }
}

但是现在有一个我真的不明白的错误（我将代码中的位置标记为注释）：

'required' initializer 'init(value:schema') must be provided by subclass of 'Object'

起初还可以：文档中没有提到任何内容。上面写着我只需要从Object inerhit 就可以了。

如果我现在添加这个方法，我会得到另一个错误：

'required' initializer 'init(value:schema') must be provided by subclass of 'Object'

第一个错误是由于缺少方法：

required init(realm: RLMREalm, schema: RLMObjectSChema) {
    fatalError("init(realm:schema:) has not been implemented")
}

第二个因为失踪：

required init(realm: RLMREalm, schema: RLMObjectSChema) {
    fatalError("init(realm:schema:) has not been implemented")
}

所以我一遍又一遍地遇到同样的错误，他总是希望我实现一个已经存在的方法。

我实际上需要做什么才能使用 RealmSwift？

【问题讨论】：

几天前我处理了同样的问题。我认为他们要求您的对象都具有其属性的默认值，然后在需要时使用便利初始化程序。这里有一个关于这个问题的完整主题：github.com/realm/realm-cocoa/issues/3185

标签： ios swift realm

【解决方案1】：

你的模型声明让我想到了两个问题：

您希望保留的属性需要对其应用dynamic 修饰符，但有少数例外。有关示例，请参见 property declaration cheatsheet。
Any initializers you add to your Object subclass must be convenience initializers.

【讨论】：