如何在Swift中從Detail ViewController更新tableview數組

Question

在我的應用程序中，我有主屏幕，該屏幕在表格視圖中顯示電子郵件列表。 單擊任何電子郵件后，我們將重定向到電子郵件詳細信息屏幕，在該屏幕上我們可以更新電子郵件狀態（例如，爭議，已付款和未決），還可以將狀態從未讀更改為已讀電子郵件。

在詳細信息屏幕上更改電子郵件的狀態后，當我從詳細信息視圖彈出到電子郵件列表時，還希望在表視圖中針對該特定電子郵件更新電子郵件列表。

struct NewHomeModel {
var body: String?
var date : String?
var dispute: Int?
var fileStatus: Int?
var from: String?
var msg_id: String?
var paid: Int?
var pending: Int?
var subject: String?
var thread_id: String?
var unread : Int?
var nextToken : String?

init(jsonData: [String: Any]) {
    body = jsonData["body"] as? String ?? ""
    date = jsonData["date"] as? String ?? ""
    dispute = jsonData["dispute"] as? Int ?? 0
    fileStatus = jsonData["fileStatus"] as? Int ?? 0
    from = jsonData["from"] as? String ?? ""
    msg_id = jsonData["msg_id"] as? String ?? ""
    paid = jsonData["paid"] as? Int ?? 0
    pending = jsonData["pending"] as? Int ?? 0
    subject = jsonData["subject"] as? String ?? ""
    thread_id = jsonData["thread_id"] as? String ?? ""
    unread = jsonData["unread"] as? Int ?? 0
}}
 func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
    if arrayData.count > 0 && arrayData.count > indexPath.row {
        let objemail = arrayData.object(at: indexPath.row) as? NewHomeModel

        let emailDetailVC = EmailDetailViewController()
        emailDetailVC.strThreadId = (objemail?.thread_id)!
        emailDetailVC.strTitle = (objemail?.subject)!
        emailDetailVC.homeModel = objemail
        self.navigationController?.pushViewController(emailDetailVC, animated: true)
    }else{
        print("array empty")
    }
}

Answer 1

detailvie當選擇了表格視圖單元格時，執行segue或推送EmailDetailViewController 。 將所選的NewHomeModel對象傳遞給EmailDetailViewController 。

class MainViewController: UITableViewController {
    var arrayData:[NewHomeModel] = [NewHomeModel]()
    //...
    override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        if arrayData.count > 0 && arrayData.count > indexPath.row {
            let objemail = arrayData[indexPath.row]

            let emailDetailVC = EmailDetailViewController()
            emailDetailVC.strThreadId = (objemail.thread_id)!
            emailDetailVC.strTitle = (objemail.subject)!
            emailDetailVC.homeModel = objemail
            emailDetailVC.callBack = { [weak self] objemail in
                self?.arrayData[indexPath.row] = objemail
                self?.tableView.reloadRows(at: [indexPath], with: .automatic)
            }
            self.navigationController?.pushViewController(emailDetailVC, animated: true)
        }else{
            print("array empty")
        }
    }
}

配置EmailDetailViewController與所選擇的NewHomeModel對象。 根據需要在此視圖控制器中更新對象的值。 返回MainViewController ，使用callBack閉包將更新后的對象傳遞給先前的視圖控制器。

class EmailDetailViewController: UIViewController {
    var strThreadId:String?
    var strTitle :String?
    var homeModel: NewHomeModel?
    var callBack: ((NewHomeModel)->Void)?
    override func viewDidLoad() {
        super.viewDidLoad()
        homeModel?.unread = 0
        //configure views with selectedModel
    }
    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        if self.isMovingFromParent, let homeModel = homeModel {
            print("Going back to main view controller")
            callBack?(homeModel)
        }
    }
    func updateStatus() {
        homeModel?.dispute = 1
        homeModel?.paid = 1
        homeModel?.pending = 0
        homeModel?.unread = 0
    }
}

在MainViewController的callBack閉包中，替換數據源數組中的更新對象，然后重新加載tableview 。

Answer 2

您可以創建Delegate方法來重新加載數據。

protocol NewHomeDelegate: NSObjectProtocol {
func reloadData()
}

之后創建委托變量

weak var delegate: NewHomeDelegate? 

並從牙科視圖控制器調用它。

調用該委托函數並刷新數據