每当我尝试运行我的应用程序时sectionNameKeyPath不是nil，它就会因错误而崩溃
*由于未捕获的异常'NSRangeException'而终止应用程序，原因：'* - [__ NSArray0 objectAtIndex：]：索引0超出空NSArray的边界'
但每当我将其设置为nil时，它就会起作用并添加一些数据，退出应用程序，将 sectionNameKeyPath 设置回我的Core Data属性，现在它可以正常工作！这是今天的第7个小时我正在与这个bug斗争，我无法解决它。我的代码有什么问题？
//
// ViewController.swift
// Expense Manager
//
// Created by Andrei Vataselu on 10/3/17.
// Copyright © 2017 Andrei Vataselu. All rights reserved.
//
import UIKit
import SideMenu
import CoreData
import SwipeCellKit
let green = UIColor(red:0.00, green:0.62, blue:0.45, alpha:1.0)
let red = UIColor(red:0.95, green:0.34, blue:0.34, alpha:1.0)
let appDelegate = UIApplication.shared.delegate as? AppDelegate
var userMoney : [UserMoney] = []
var managedObjectContext: NSManagedObjectContext? = appDelegate?.persistentContainer.viewContext
class ViewController: UIViewController, NSFetchedResultsControllerDelegate {
@IBOutlet weak var sumTextField: UITextField!
@IBOutlet weak var userBudgetLabel: UILabel!
@IBOutlet var tap: UITapGestureRecognizer!
@IBOutlet weak var topView: UIView!
@IBOutlet weak var plusButton: UIButton!
@IBOutlet weak var tableView: UITableView!
@IBOutlet weak var moreBtn: UIButton!
func userBudgetCount(_ section: Int) -> Int{
return fetchedResultsController.sections![section].numberOfObjects
}
func getUserBudgetAtIndexPath(indexPath : IndexPath) -> Budget {
return fetchedResultsController.object(at: indexPath) as Budget
}
override func viewDidLoad() {
super.viewDidLoad()
self.hideKeyboard()
tableView.delegate = self
tableView.dataSource = self
self.tableView.tableFooterView = UIView()
}
override func viewDidAppear(_ animated: Bool) {
super.viewWillAppear(animated)
fetchCoreDataObject()
}
func fetchCoreDataObject() {
self.fetch { (complete) in
if complete {
if userBudgetCount(0) >= 1 {
userBudgetLabel.text = replaceLabel(number: userMoney[userMoney.count - 1].userMoney)
tableView.isHidden = false
plusButton.isHidden = false
moreBtn.isHidden = false
} else {
tableView.isHidden = true
userBudgetLabel.text = "Bugetul tau"
plusButton.isHidden = true
moreBtn.isHidden = true
}
}
}
}
var fetchedResultsController: NSFetchedResultsController<Budget> {
if _fetchedResultsController != nil {
return _fetchedResultsController!
}
let fetchRequest = NSFetchRequest<Budget>(entityName: "Budget")
// Set the batch size to a suitable number.
fetchRequest.fetchBatchSize = 20
// Edit the sort key as appropriate.
let sortDescriptor = NSSortDescriptor(key: "dateSubmitted" , ascending: false)
fetchRequest.sortDescriptors = [sortDescriptor]
// Edit the section name key path and cache name if appropriate.
// nil for section name key path means "no sections".
let aFetchedResultsController = NSFetchedResultsController(fetchRequest: fetchRequest, managedObjectContext: managedObjectContext!, sectionNameKeyPath: "dateSection", cacheName: nil)
aFetchedResultsController.delegate = self
_fetchedResultsController = aFetchedResultsController
do {
try _fetchedResultsController!.performFetch()
} catch {
// Replace this implementation with code to handle the error appropriately.
// fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
let nserror = error as NSError
fatalError("Unresolved error \(nserror), \(nserror.userInfo)")
}
return _fetchedResultsController!
}
var _fetchedResultsController: NSFetchedResultsController<Budget>? = nil
func controller(_ controller: NSFetchedResultsController<NSFetchRequestResult>, didChange anObject: Any, at indexPath: IndexPath?, for type: NSFetchedResultsChangeType, newIndexPath: IndexPath?) {
tableView.reloadData()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
@IBAction func initialAddButtonPressed(_ sender: Any) {
if sumTextField.text != "" {
self.saveMoney(userMoney: (sumTextField.text! as NSString).doubleValue, completion: { (complete) in
})
self.save(sumText: sumTextField.text! , dataDescription: "Buget initial", dataColor: green) {
complete in
if complete {
tableView.isHidden = false
}
}
userBudgetLabel.text = "\(sumTextField.text!) RON"
self.fetchCoreDataObject()
tableView.reloadData()
} else {
sumInvalidAlert()
}
self.dismissKeyboard()
sumTextField.text = ""
}
@IBAction func plusButtonPressed(_ sender: Any) {
let plusController = UIAlertController(title: nil, message: nil, preferredStyle: .actionSheet)
let addBudgetAction = UIAlertAction(title: "Adauga buget", style: .default) {
(action) -> Void in
guard let createAddBudgetVC = self.storyboard?.instantiateViewController(withIdentifier: "AddBudgetVC") else { return }
self.presentViewController(createAddBudgetVC)
}
let addExpenseAction = UIAlertAction(title: "Adauga plata", style: .default) {
(action) -> Void in
guard let createAddExpenseVC = self.storyboard?.instantiateViewController(withIdentifier: "AddExpenseVC") else { return }
self.presentViewController(createAddExpenseVC)
}
let cancelAction = UIAlertAction(title: "Anuleaza", style: .cancel, handler: nil)
plusController.addAction(addBudgetAction)
plusController.addAction(addExpenseAction)
plusController.addAction(cancelAction)
present(plusController, animated: true, completion: nil)
}
@IBAction func moreButtonPressed(_ sender: Any) {
}
}
extension ViewController {
func fetch(completion: (_ complete: Bool) -> ()){
guard let managedContext = appDelegate?.persistentContainer.viewContext else { return }
let fetchMoneyRequest = NSFetchRequest<UserMoney>(entityName: "UserMoney")
do{
userMoney = try managedContext.fetch(fetchMoneyRequest)
print("success")
completion(true)
} catch {
debugPrint("Could not fetch \(error.localizedDescription)")
completion(false)
}
}
func removeCell(atIndexPath indexPath: IndexPath){
guard let managedContext = appDelegate?.persistentContainer.viewContext else { return }
do {
try managedContext.save()
debugPrint("removeCell CONTEXT SAVED")
} catch {
debugPrint("removeCell CONTEXT NOT SAVED \(error.localizedDescription)")
}
}
func cancelCell(color: UIColor, atIndexPath indexPath: IndexPath){
guard let managedContext = appDelegate?.persistentContainer.viewContext else { return }
if color.description == green.description {
// scade buget
userMoney[userMoney.count - 1].userMoney -= (getUserBudgetAtIndexPath(indexPath: indexPath).dataSum! as NSString).doubleValue
} else {
userMoney[userMoney.count - 1].userMoney += (getUserBudgetAtIndexPath(indexPath: indexPath).dataSum! as NSString).doubleValue
}
do {
try managedContext.save()
} catch {
print("cancelCell Managed Context Saving ERROR: \(error.localizedDescription)")
}
}
}
extension ViewController: UITableViewDelegate, UITableViewDataSource,SwipeTableViewCellDelegate {
func tableView(_ tableView: UITableView, editActionsForRowAt indexPath: IndexPath, for orientation: SwipeActionsOrientation) -> [SwipeAction]? {
guard orientation == .right else {
let cancelAction = SwipeAction(style: .default, title: "Anuleaza"){
(action, indexPath)
in
self.cancelCell(color: self.getUserBudgetAtIndexPath(indexPath: indexPath).dataColor as! UIColor, atIndexPath: indexPath)
self.removeCell(atIndexPath: indexPath)
self.fetchCoreDataObject()
tableView.deleteRows(at: [indexPath], with: .automatic)
}
cancelAction.backgroundColor = UIColor(red:0.16, green:0.63, blue:0.74, alpha:1.0)
return [cancelAction]
}
let deleteAction = SwipeAction(style: .destructive, title: "Sterge") { (action, indexPath) in
self.removeCell(atIndexPath: indexPath)
self.fetchCoreDataObject()
tableView.deleteRows(at: [indexPath], with: .automatic)
}
deleteAction.backgroundColor = red
return [deleteAction]
}
func numberOfSections(in tableView: UITableView) -> Int {
if let sections = fetchedResultsController.sections {
return sections.count
}
return 0
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
guard let cell = tableView.dequeueReusableCell(withIdentifier: "expenseCell") as? ExpenseCell else { return UITableViewCell() }
print("indexPathRow: \(indexPath.row) | indexPathSection: \(indexPath.section)")
let budget = fetchedResultsController.object(at: indexPath) as Budget
cell.delegate = self
cell.configureCell(budget: budget)
return cell
}
func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
return true
}
func tableView(_ tableView: UITableView, editingStyleForRowAt indexPath: IndexPath) -> UITableViewCellEditingStyle {
return UITableViewCellEditingStyle.none
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
if let sections = fetchedResultsController.sections {
let currentSection = sections[section]
return currentSection.numberOfObjects
}
return 0
}
func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
if let sections = fetchedResultsController.sections {
let currentSections = sections[section]
return currentSections.name
}
return nil
}
}