*** 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 的范围

Question

为什么我总是收到以下错误

* 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 的范围” *** 首先抛出调用堆栈： (0x183702db0 0x182d67f80 0x1836799ac 0x18d48f6d4 0x10003999c 0x100039b04 0x188860c40 0x1888790d0 0x188a13e5c 0x18891fe40 0x1889 1fb1c 0x18891fa84 0x194f41fd0 0x18885c1e4 0x1861ee994 0x1861e95d0 0x1861e9490 0x1861e8ac0 0x1861e8820 0x18885eff4 0x1836b909c 0x18 36b8b30 0x1836b6830 0x1835e0c50 0x184ec8088 0x1888ca088 0x10003fd7c 0x18317e8b8) libc++abi.dylib：以 NSException 类型的未捕获异常终止

下面给出了我的初始视图控制器的代码

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()



}
}

Answer 1

它崩溃了，因为数组

self.entries

不包含任何对象。您应该在刷新表格之前检查一下。

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()
    }

}

Answer 2

你试过这个吗：

1. 单击您的表格视图
2. 转到属性检查器
3. 将内容从

   Static Cells

   更改为

   Dynamic Prototypes

Answer 3

我在 React Native 上也面临着同样的问题。 将 react-native-screen 更新到最新版本解决了我的问题。