为什么我不断收到以下错误
下面给出了我的初始 View Controller 的代码
import UIKit
import CoreData
class NotesListTableViewController: UITableViewController {
var managedObjectContext : NSManagedObjectContext!
var entries: [NSManagedObject]!
override func viewDidLoad()
{
super.viewDidLoad()
let appDelegate = UIApplication.sharedApplication().delegate as! AppDelegate
managedObjectContext = appDelegate.managedObjectContext
//self.fetchEntries()
// makes the searchbar stay in the current screen and not spill into the next screen
//definesPresentationContext = true
// Uncomment the following line to preserve selection between presentations
// self.clearsSelectionOnViewWillAppear = false
// Uncomment the following line to display an Edit button in the navigation bar for this view controller.
// self.navigationItem.rightBarButtonItem = self.editButtonItem()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
// MARK: - Table view data source
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int
{
return self.entries.count
}
override func numberOfSectionsInTableView(tableView: UITableView) -> Int
{
return 1
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell
{
let cell = tableView.dequeueReusableCellWithIdentifier("NotesCell", forIndexPath: indexPath)
// Configure the cell...
let entry1 = entries[indexPath.row]
cell.textLabel?.text = entry1.valueForKey("entry_body") as? String
let imageData2 = entry1.valueForKey("entry_image") as? NSData
if let imageData2 = imageData2
{
let myimage = UIImage(data:imageData2,scale:1.0)
cell.imageView?.image = myimage
}
return cell
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?)
{
if segue.identifier! == "showNote"
{
let detailDisplay = segue.destinationViewController as! DetailDisplayViewController
let selectedIndexPath = tableView.indexPathForSelectedRow!
let entry = entries[selectedIndexPath.row]
detailDisplay.entry = entry
}
}
override func tableView(tableView: UITableView, commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath)
{
let entry1 = self.entries[indexPath.row]
self.managedObjectContext.deleteObject(entry1)
self.entries.removeAtIndex(indexPath.row)
self.tableView.deleteRowsAtIndexPaths([indexPath], withRowAnimation: .Automatic)
do
{
try managedObjectContext.save()
} catch {
print ("could not save the new entry ")
}
}
override func viewWillAppear(animated: Bool)
{
super.viewWillAppear(animated)
self.tabBarController?.tabBar.hidden = false
self.fetchEntries()
}
func fetchEntries()
{
let fetchRequest = NSFetchRequest(entityName:"Entry")
do {
let entryObjects = try managedObjectContext.executeFetchRequest(fetchRequest)
self.entries = entryObjects as! [NSManagedObject]
}catch let error as NSError
{
print ("could not save the new entry \(error.description) ")
}
tableView.reloadData()
}
}
最佳答案
它崩溃是因为数组 self.entries 不包含任何对象。您应该在刷新表之前检查它。
func fetchEntries()
{
let fetchRequest = NSFetchRequest(entityName:"Entry")
do {
let entryObjects = try managedObjectContext.executeFetchRequest(fetchRequest)
self.entries = entryObjects as! [NSManagedObject]
}catch let error as NSError
{
print ("could not save the new entry \(error.description) ")
}
if !self.entries.isEmpty // if your array is not empty refresh the tableview
{
tableView.reloadData()
}
}
关于ios - *** 由于未捕获的异常 'NSRangeException' 终止应用程序，原因是 : '*** -[__NSArray0 objectAtIndex:]: index 0 beyond bounds for empty NSArray，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/38304437/