Question

我有以下结构：

    struct PalletScan: Codable {
            var deliveryId: String?
            var userId: String?
            var timestamp: String?
            var tempPalletNr: String?
            var tempLocation: String?
            var tempPalletType: String?
            var pallets: [MovementScan]?

            //coding keys requried for translation API -> struct -> CoreData and CoreData -> struct -> API
            enum CodingKeys: String, CodingKey {
                case deliveryId = "TOID"
                case userId = "UserId"
                case timestamp = "TimeStamp"
            }

    mutating func appendMovementScan() {
                var movementScan = MovementScan()
                movementScan.locationId = self.tempLocation
                movementScan.palletId = self.tempPalletNr
                movementScan.palletType = self.tempPalletType
                movementScan.timestamp = String(Date().timeIntervalSince1970)
                print(movementScan)
                self.pallets?.append(movementScan)

            }

}

但是self.pallets?.append(movementScan)没有向托盘数组添加任何内容。我错过了什么？它必须是微不足道的，但不能发现错误。

Answer 1

只需更改var pallets: [MovementScan]?
以 var pallets: [MovementScan] = [MovementScan]()

作为@Carcigenicate你调用附加值nil值

Answer 2

var pallet未初始化并且是可选的，所以当你使用附加运动扫描时？，它不会被执行。

要解决此问题，您必须先了解如何在附加托盘数组之前对其进行初始化。一种方法可以简单地用空数组初始化：

var pallets = [MovementScan]()

将数组值附加到struct

2 个答案: