'NSInternalInconsistencyException'，原因：“试图将第4行插入第0节，但更新后第0节只有4行”

Question

Ok I've seen previous questions in obj C and tried them. What i'm trying to build is a Contacts app similar to iphone one. I'm having this problem in inserting row in my table. Earlier before I never had this problem with inserting rows I probably think it is because of my bad data structure?

The solution I tried was tableView.beginUpdates and endUpdates but still same error. Here's my code for contact list.

    class ContactsListViewController:  UITableViewController, AddContactViewControllerDelegate {

    let cellID = "contactCellID"
    var sectionNames = ["A","B","C","D"]
    var name = [0: ["Amber", "Ajay", "Abhishek", "Anshul"], 1: ["Borat", "Bruno", "Billooo"], 2: ["Chinku","Champu","Champak"], 3: ["Daya", "Divya","Delhi Police"]]

//    
//    @IBOutlet weak var addBarOutlet: UIBarButtonItem!
//    @IBAction func addBarButton(sender: UIBarButtonItem) {
//        performSegueWithIdentifier("AddItemSegueID", sender: addBarOutlet)
//    }
//   

    //var nameSet = ["0": "Amber", "1": "Blah", "2": "Chris" ]
    override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
        return name.count
    }

    override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {

        let array = name[section]
        return (array!.count)
    }
    override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCellWithIdentifier(cellID, forIndexPath: indexPath)
        let nameArray = name[indexPath.section]
//        guard let nameArray = name[indexPath.section] else {
//            print("Invalid ")
//            cell.textLabel?.text = "Not Found"
//            return cell
//        }

        cell.textLabel?.text = nameArray![indexPath.row]
        return cell
    }
    override func tableView(tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
        var Keys = [Int] (name.keys)
        Keys.sortInPlace()
        let value = Keys[section]
        var sec = ""
        if value == Keys[section] {
            sec = sectionNames[section]
        }
        return sec

    }
    override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {

        tableView.deselectRowAtIndexPath(indexPath, animated: true)
    }

    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
        if segue.identifier == "AddItemSegueID" {
           // let navcontroller = segue.destinationViewController as! UINavigationController
           // let controller = navcontroller.topViewController as! AddContactViewController
            let controller = segue.destinationViewController as! AddContactViewController
            controller.delegate = self
        }
    }

    func addContactViewController(controller: AddContactViewController, didFinishAdding item: ContactNames) {

        //var dictKeys = [Int](name.keys)
        let newName = item.text
        let firstIndex = newName.startIndex
        //let firstChar = newName[firstIndex]
        var check = name[0]!

        let newRowIndex = check.count

        check.append(newName)
        tableView.beginUpdates()
        let indexPath = NSIndexPath(forRow: newRowIndex, inSection: 0)
        let indexPaths = [indexPath]
        tableView.insertRowsAtIndexPaths(indexPaths, withRowAnimation: .Automatic)
        tableView.endUpdates()

        dismissViewControllerAnimated(true, completion: nil)
    }
    func addContactViewControllerDidCancel(controller: AddContactViewController) {
        dismissViewControllerAnimated(true, completion: nil)
    }
}

---

---

ContactNames is normal swift class that coontains a string property. The other thing is i implemented a protocol in AddItemVC in order to send data back to pervious view controller so i made a delegate which i also learnt recently. Heres yhe addItemVC:

 protocol AddContactViewControllerDelegate: class {

    func addContactViewControllerDidCancel(controller: AddContactViewController)
    func addContactViewController(controller: AddContactViewController, didFinishAdding item: ContactNames)
}

class AddContactViewController: UIViewController, UITextFieldDelegate {


    weak var delegate: AddContactViewControllerDelegate?

    @IBOutlet weak var nameField: UITextField!

    @IBOutlet weak var doneOutlet: UIBarButtonItem!

    var contactList = ContactsListViewController()
    override func viewDidLoad() {
        nameField.becomeFirstResponder()
        self.tabBarController?.tabBar.hidden = true
        doneOutlet.enabled = false
    }

    override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
        nameField.resignFirstResponder()

    }
    func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
        let oldText: NSString = textField.text!
        let newText: NSString = oldText.stringByReplacingCharactersInRange(range, withString: string)
        doneOutlet.enabled = (newText.length>0)
//        if newText.length > 0 {
//            doneOutlet.enabled = true
//        }else {
//            doneOutlet.enabled = false
//        }

        return true
    }

    @IBAction func saveAction(sender: UIBarButtonItem) {
        let newItem = ContactNames()
        newItem.text = nameField.text!

        delegate?.addContactViewController(self, didFinishAdding: newItem)

    }
    @IBAction func cancelAction(sender: UIBarButtonItem) {
        delegate?.addContactViewControllerDidCancel(self)
    }
}

Also if you suggest a better data structure for this.

Answer 1

The native collection types in Swift are value types that means the objects are always copied when you get a value for a key or for an index.

You assign the array for key "0" to variable check and append a value

var check = name[0]!
...
check.append(newName)

but that does not change the original array in dictionary name . You need to assign the array back to the dictionary

name[0] = check

Isn't it more convenient to use the actual letters for the keys rather than unrelated numbers?

Answer 2

Between beginUpdates and endUpdates, you need to update your data source so that it matches the operations like insertRowsAtIndexPaths. So if you had four rows, and insert one as you do, your data source must also be changed to now have five rows. Exactly as the error message says.