Swift：JSONEcoder EXC

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我想在我的Swift应用程序中对一些对象进行编码和解码。我有以下2类。

I want to encode and decode some objects in my Swift app. I have the following 2 classes.

enum TileSize : Int, Codable { case smallTile = 3 case mediumTile = 2 case largeTile = 1 } class Tile: NSObject, Codable { var tileSize: TileSize = .smallTile var imageName: String = ""; var isDragged = false private enum CodingKeys : String, CodingKey { case tileSize case imageName } } class ConsumptionTile: Tile { override var imageName: String { get { return "consumption" } set { super.imageName = newValue } } }

这是代码，说明我如何编码对象。

And here is the code, how I try to encode the objects.

var defaultTiles : [Tile] = [] defaultTiles.append(ConsumptionTile(tileSize: .largeTile)) defaultTiles.append(Tile(tileSize: .largeTile, imageName: "my-devices")) defaultTiles.append(Tile(tileSize: .mediumTile, imageName: "live-verbrauch")) defaultTiles.append(Tile(tileSize: .smallTile, imageName: "zaehlerstand")) defaultTiles.append(Tile(tileSize: .smallTile, imageName: "vertrag")) let jsonEncoder = JSONEncoder() let jsonData = try jsonEncoder.encode(defaultTiles)

我认为问题是，我尝试对ConsumptionTile子类的对象进行编码，但Array类型为[Tile]。但我不知道该如何解决。我必须将所有Tile类编码为一个数据对象。稍后将有更多的子类，而不仅仅是ConsumptionTile。

I think the problem is, that I try to encode an object of the subclass ConsumptionTile but the Array is of type [Tile]. But I don't know how to solve this. I have to to encode all Tile-classes to one data object. Later there will be more subclasses and not just the ConsumptionTile.

我在运行时遇到的错误只是尝试jsonEncoder.encode（defaultTiles）行上的断点与消息线程1：EXC_BAD_ACCESS（代码= 1，地址= 0x8）

The error I get on runtime is just a breakpoint on the try jsonEncoder.encode(defaultTiles) line with the message Thread 1: EXC_BAD_ACCESS (code=1, address=0x8)

我希望有人可以提供帮助。谢谢！

I hope someone can help. Thank you!

推荐答案

我只是在操场上尝试过，但无法重现该错误。唯一潜在的问题是通过编码-解码过程丢失类型信息，其中 ConsumptionTile 被解码为 Tile 。

I just tried it in the playground, and I wasn't able to reproduce the error. The only potential problem was the loss of the type information through the encode - decode process, where the ConsumptionTile is decoded as a Tile.

如果将其放在

import Foundation enum TileSize : Int, Codable { case smallTile = 3 case mediumTile = 2 case largeTile = 1 } class Tile: NSObject, Codable { var tileSize: TileSize = .smallTile var imageName: String = ""; var isDragged = false init(tileSize: TileSize, imageName: String) { self.tileSize = tileSize self.imageName = imageName } private enum CodingKeys : String, CodingKey { case tileSize case imageName } } class ConsumptionTile: Tile { init(tileSize: TileSize) { super.init(tileSize: tileSize, imageName: "") } required init(from decoder: Decoder) throws { fatalError("init(from:) has not been implemented") } override var imageName: String { get { return "consumption" } set { super.imageName = newValue } } } var defaultTiles : [Tile] = [] defaultTiles.append(ConsumptionTile(tileSize: .largeTile)) defaultTiles.append(Tile(tileSize: .largeTile, imageName: "my-devices")) defaultTiles.append(Tile(tileSize: .mediumTile, imageName: "live-verbrauch")) defaultTiles.append(Tile(tileSize: .smallTile, imageName: "zaehlerstand")) defaultTiles.append(Tile(tileSize: .smallTile, imageName: "vertrag")) let jsonEncoder = JSONEncoder() let jsonData = try! jsonEncoder.encode(defaultTiles) let out = try! JSONDecoder().decode([Tile].self, from: jsonData) for tile in out { print(">>> \(tile.imageName)") }