如何在swift中通过转场传递一个变量？

Question

这是我的main中的代码块 UITableViewController 以班级 InventoryTableViewController

 override func prepare(for segue: UIStoryboardSegue, sender: Any?) {

        super.prepare(for: segue, sender: sender)
        switch segue.identifier! {
            case "detailSegue":
                guard let inventoryDetail = segue.destination as? InventoryDetailView else {
                    fatalError("Unexpected destination: \(segue.destination)")
                }
                guard let selectedVehicleCell = sender as? InventoryTableViewCell else {
                    fatalError("Unexpected sender: \(String(describing: sender))")
                }
                guard let indexPath = tableView.indexPath(for: selectedVehicleCell) else {
                    fatalError("The selected cell is not being displayed by the table")
                }
                let selectedVehicle = vehicles[indexPath.row]
                inventoryDetail.vehicle = selectedVehicle as? InventoryDetailView.Inventory
                printGenericInfo(selectedVehicle)
                default:
                fatalError("Unexpected Segue Identifier; \(String(describing: segue.identifier))")
        }
   }

   func printGenericInfo<T>(_ value: T) {

        let t = type(of: value as Any)
        print("'\(value)' of type '\(t)'")
   }

我试图传递 selectedVehicle。当我打印值和类型时，它的值和类型如下（并且是正确的）。

Inventory(id: 1004，年份： "2014"，make："MakeWith15Chars"，model： "MakeWith15Chars"，model: "ModelWith15Char"，body: "BodyWith15Chars", 内饰: "山核桃木"，外观： "Magnetic Gray", vin: "2C4RDGCG0FR805928", miles: "10450", msrp: "33,800.00"，成本："28,100.00"）的类型库存。

我的代码块 InventoryDetailView 是这样的。

class InventoryDetailView: UIViewController {

    var vehicle: Inventory!
    struct Inventory: Hashable, Codable, Identifiable {
                var id: Int
                var year: String
                var make: String
                var model: String
                var body: String
                var interior: String
                var exterior: String
                var vin: String
                var miles: String
                var msrp: String
                var cost: String
    }
    override func viewDidLoad() {
        super.viewDidLoad()
        yearMakeLabel.text = vehicle?.year
    }
}

当我在InventoryDetailView中打印车辆的价值时，是nil. 为什么会这样？我到底做错了什么？

Answer 1

我认为，首先，你要删除这行内容。super.prepare(for: segue, sender: sender) 因为你不需要叫它