如何在 MasterViewController 更新时刷新 DetailViewController

Question

我有一个应用程序，用户可以在其中更新和添加任务。但是当用户更新任务时，我需要更新 DetailViewController

中的详细信息

当用户更新任务并保存MasterViewController中的数据时，DetailViewController中的数据保持不变

我怎样才能修复它以便更新详细信息

使用 AddProjectController

添加和编辑任务

我尝试了以下方法，但none如果它们有效，都会导致应用程序崩溃

 let vc = DetailViewController()
 let row = vc.view.layoutIfNeeded();

//Second method

let vc = MasterViewController() 
vc.performSegue(withIdentifier: "showDetail", sender: vc.self)

使用

在DetailViewController中设置数据

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

        lblName.text = detail.name ?? ""
        lblCode.text = detail.code ?? ""     
    }

MasterViewController

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "showDetail" {
   if let indexPath = tableView.indexPathForSelectedRow {
       let object = fetchedResultsController.object(at: indexPath)
       let controller = (segue.destination as! UINavigationController).topViewController as! DetailViewController
                controller.details = object;
                controller.navigationItem.leftBarButtonItem = splitViewController?.displayModeButtonItem
                controller.navigationItem.leftItemsSupplementBackButton = true
                detailViewController = controller
            }
    }
}

编辑视图控制器

func editEvents(_ sender: Any){
        let fetchRequest: NSFetchRequest<NSFetchRequestResult> = NSFetchRequest(entityName: "Proj")

        do {
            let test = try context.fetch(fetchRequest)

            var objectUpdate = test[0] as! Assesment;


            objectUpdate.name = txtname.text ?? ""
            objectUpdate.code = txtCode.text ?? "";

            do {
                try context.save()

            }
            catch {
                print(error)
            }
        }
        catch {
            print(error)
        }
    }

我想在 editEvent 函数执行完毕后更新详情

有什么方法可以让它工作吗？

Answer 1

如果你正在使用 coreData ..你可以详细实现 FRC ..这样你每次在回调中都能得到刷新的数据......

在你的MasterViewController中定义一个变量

这是另一个解决方法

private var controller : DetailViewController? = nil

然后在你的 Segue 方法中使用这个控制器

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "showDetail" {
   if let indexPath = tableView.indexPathForSelectedRow {
       let object = fetchedResultsController.object(at: indexPath)
       self.controller = (segue.destination as! UINavigationController).topViewController as! DetailViewController // here you set your instence variable controller
                controller.details = object;
                controller.navigationItem.leftBarButtonItem = splitViewController?.displayModeButtonItem
                controller.navigationItem.leftItemsSupplementBackButton = true
                detailViewController = controller
            }
    }
}


func editEvents(_ sender: Any){
        let fetchRequest: NSFetchRequest<NSFetchRequestResult> = NSFetchRequest(entityName: "Proj")

        do {
            let test = try context.fetch(fetchRequest)

            var objectUpdate = test[0] as! Assesment;


            objectUpdate.name = txtname.text ?? ""
            objectUpdate.code = txtCode.text ?? "";



            do {
                try context.save()
                if let detailsCotrollerExists = controller {
                 detailsCotrollerExists.updateDataWithObject(objectUpdate) // function you will write in detail class which takes object and refresh data there .. Either outlets or Table/Collection View reload
                }
            }
            catch {
                print(error)
            }
        }
        catch {
            print(error)
        }
    }

然后你在 DetailViewController 中写一个函数 func updateDataWithObject(_ obj: Assesment) 你将详细写的函数 class 它获取对象并在那里刷新数据.. 出口或 Table/Collection 查看重新加载在DetailViewController

中写入函数

func updateDataWithObject(_ obj: Assesment) {
  // Refresh data
}

如何在 MasterViewController 更新时刷新 DetailViewController

How to refresh DetailViewController when MasterViewController is updated

ios

swift

uisplitviewcontroller