swift - 删除、添加和显示数据 swift TableView Controller

Question

我是我的 Swift 应用程序，我需要在表格 View 中显示数据。服务器端的数据经常发生变化，因此我需要删除以前的所有数据并添加获取的新数据。我能够删除和获取，并且可以在控制台和 Realm 浏览器中看到新数据。但是，数据在结果的 TableView Controller 中不可用。

class ServiceProvidersTableViewController: UITableViewController {    
    // MARK: - Data Source
    var serviceSubCategory: String = ""
    var serviceSubCategories: Results<ServiceSubCategory>?

    // MARK: - Realm
    let realm = try! Realm()
    let fetchData = FetchData()

    override func viewDidLoad() {
        super.viewDidLoad()

        self.deleteSubCategories()

        FetchData.get(ServiceSubCategory.self, params: ["subCategoryId": serviceSubCategory], success: {            
            self.infoAlert("Service Categories", message: "Fetch Successful")
        }) {
            self.infoAlert("Failed", message: "Fetch Failed")
        }
        self.fetchSubCategories()
    }

    func deleteSubCategories()
    {
        let subCategories = realm.objects(ServiceSubCategory.self)
        print("Before delete \(subCategories)")
        try! realm.write{
            realm.delete(subCategories)
        }
        print("After delete \(subCategories)")
    }

    func fetchSubCategories() {
        self.realm.refresh()
        self.serviceSubCategories = self.realm.objects(ServiceSubCategory)
        tableView.reloadData()
        print("After fetch \(self.serviceSubCategories)")
    }

    struct Storyboard {
        static let CellIndentifier = "ServiceProvidersCell"
    }


    // MARK: - Table view data source

    override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
        // #warning Incomplete implementation, return the number of sections
        return 1
    }

    override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        // #warning Incomplete implementation, return the number of rows
        print(self.serviceSubCategories!.count)
        return self.serviceSubCategories!.count


    }

    override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCellWithIdentifier(Storyboard.CellIndentifier, forIndexPath: indexPath) as! ServiceProvidersTableViewCell
       print(serviceSubCategories)
        cell.serviceSubCategories = self.serviceSubCategories![indexPath.row]
        return cell
    }

    func infoAlert(title:String,message:String) -> Void {
        let actionSheetController: UIAlertController = UIAlertController(title:title, message:message, preferredStyle: .Alert)
        let cancelAction: UIAlertAction = UIAlertAction(title: "Cancel", style: .Cancel) { action -> Void in }
        actionSheetController.addAction(cancelAction)
        self.presentViewController(actionSheetController, animated: true, completion: nil)
    }
}

Answer 1

我的猜测是，您需要从本地“serviceSubCategory”中删除该对象，而不仅仅是从服务器中删除。

每次服务器监听器触发时放置一个tableView.reloadData()。

可能在 fetchSubCategories() 和 deleteSubCategories() 函数中。