ios - swift 5 : Display Data Retrieved in Closure to Table View

Question

我已经在函数的闭包中成功地从我的 API 获取了一些数据。我需要将数据显示到 Storyboard上的表格中。

我知道它不显示的原因是因为数据保存在闭包中，除非我有完成处理程序，否则我无法从外部访问它。我在 Stack Overflow 上阅读了许多其他问题，但我无法真正理解。我也尝试过重新加载表，但它只返回“意外发现 nil”的错误。

声明属性

class ClaimProperties {
    var id: Int
    var date: String
    var status: String

    init(id: Int, date: String, status: String) {
        self.id = id
        self.date = date
        self.status = status
    }
}

仪表板 Controller

struct Claims: Decodable {
    let id: Int
    let submission_date: String
    let status: String
    init(json: [String:Any]) {
        id = json["id"] as? Int ?? -1
        submission_date = json["submission_date"] as? String ?? ""
        status = json["status"] as? String ?? ""
    }
}

class DashboardController: UIViewController, GIDSignInUIDelegate {

    @IBOutlet weak var tableView: UITableView!
    var tempArray: [ClaimProperties] = []

    override func viewDidLoad() {
        super.viewDidLoad()
        tableView.delegate = self
        tableView.dataSource = self
    }

    // getTokenFromAPI() gets called form AppDelegate.swift once the user logs in via Google API

    func getTokenFromAPI(usersAppToken:String) {
        guard let urlString = URL(string: "https://claim.ademo.work/claims/") else { return }
        var requestAPI = URLRequest(url: urlString)

        requestAPI.httpMethod = "GET"
        requestAPI.addValue("application/json", forHTTPHeaderField: "Content-Type")
        requestAPI.addValue("application/json", forHTTPHeaderField: "Accept")
        requestAPI.setValue("Bearer \(usersAppToken)", forHTTPHeaderField: "Authorization")

        URLSession.shared.dataTask(with: requestAPI) {
            (data, response, error) in
            if let data = data {
                do {

                    let json = try JSONDecoder().decode([Claims].self, from: data)

                    for n in 0..<json.count {
                        self.tempArray.append(ClaimProperties(id: json[n].id, date: json[n].submission_date, status: json[n].status))
                    }

                    // This is the data I'm trying to display -> tempArray

                } catch let error {
                    print("Localized Error: \(error.localizedDescription)")
                    print("Error: \(error)")
                }
            }
        }.resume()
    }
}

extension DashboardController: UITableViewDataSource, UITableViewDelegate {

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return tempArray.count
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "ClaimCell", for: indexPath) as! AllMyClaimsTable
        cell.idField.text = String(tempArray[indexPath.section].id)
        cell.dateField.text = tempArray[indexPath.section].date
        cell.statusField.text = tempArray[indexPath.section].status
        return cell
    }
}

总之，我要做的只是将 API 数据显示到我的表格 View 中。

Answer 1

移动您的reload在 for 循环下的行

URLSession.shared.dataTask(with: requestAPI) { [weak self] (data, response, error) in
    if let data = data {
        do {

            let json = try JSONDecoder().decode([Claims].self, from: data)

            for n in 0..<json.count {
                self?.tempArray.append(ClaimProperties(id: json[n].id, date: json[n].submission_date, status: json[n].status))
            }
            self?.tableView.reloadData()

        } catch let error {
            print("Localized Error: \(error.localizedDescription)")
            print("Error: \(error)")
        }
    }
}.resume()

您需要在循环结束后重新加载，在 tempArray 之后被完全填满。