Swift. SIGABRT: cast value of type '__NSCFDictionary' to 'NSMutableArray'

问题

I'm making a converter app. I want to save the conversion historic. I saw this tutorial and it works fine but when I tried to use it on my app I'm getting a SIGABRT.

Could not cast value of type '__NSCFDictionary' (0x57945c) to 'NSMutableArray' (0x5791c8)

I'm getting this at

notesArray = try NSPropertyListSerialization.propertyListWithData(data, options: NSPropertyListMutabilityOptions.MutableContainersAndLeaves, format: nil) as! NSMutableArray

EDIT:

AppDelegate:

import UIKit

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?

    var plistPathInDocument:String = String()

    func preparePlistForUse(){

        let rootPath = NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.DocumentDirectory, .UserDomainMask, true)[0]

        plistPathInDocument = rootPath.stringByAppendingString("/historic.plist")
        if !NSFileManager.defaultManager().fileExistsAtPath(plistPathInDocument){
            let plistPathInBundle = NSBundle.mainBundle().pathForResource("historic", ofType: "plist") as String!

            do {
                try NSFileManager.defaultManager().copyItemAtPath(plistPathInBundle, toPath: plistPathInDocument)
            }catch{
                print("Error occurred while copying file to document \(error)")
            }
        }
    }

    func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
        // Override point for customization after application launch.
        self.preparePlistForUse()
        return true
    }

    func applicationDidBecomeActive(application: UIApplication) {
        // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
        self.preparePlistForUse()
    }
}

ViewController:

import UIKit

class ViewControllerHistorico: UITableViewController {

    var notesArray:NSMutableArray!
    var plistPath:String!

    override func viewWillAppear(animated: Bool) {
        let appDelegate = UIApplication.sharedApplication().delegate as! AppDelegate
        plistPath = appDelegate.plistPathInDocument
        // Extract the content of the file as NSData
        let data:NSData =  NSFileManager.defaultManager().contentsAtPath(plistPath)!
        do{
            notesArray = try NSPropertyListSerialization.propertyListWithData(data, options: NSPropertyListMutabilityOptions.MutableContainersAndLeaves, format: nil) as! NSMutableArray
        }catch{
            print("Error occured while reading from the plist file")
        }
        self.tableView.reloadData()
    }

    override func tableView(tableView: UITableView,
        cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell{

            let cell:UITableViewCell! = tableView.dequeueReusableCellWithIdentifier("cellIdentifier")
            cell.textLabel!.text = notesArray.objectAtIndex(indexPath.row) as? String
            return cell
    }
    override func tableView(tableView: UITableView,
        numberOfRowsInSection section: Int) -> Int{
            return notesArray.count
    }

    override func tableView(tableView: UITableView,
        commitEditingStyle editingStyle: UITableViewCellEditingStyle,
        forRowAtIndexPath indexPath: NSIndexPath){
            // remove the row from the array
            notesArray.removeObjectAtIndex(indexPath.row)
            self.tableView.deleteRowsAtIndexPaths([indexPath], withRowAnimation: UITableViewRowAnimation.Fade)
            notesArray.writeToFile(plistPath, atomically: true)
    }
}

historic.plist

回答1:

You are trying to cast a Dictionary into a NSMutableArray.

You could save it as a Dictionary by changing your code to:

var notesDict: NSMutableDictionary = try NSPropertyListSerialization.propertyListWithData(data, options: NSPropertyListMutabilityOptions.MutableContainersAndLeaves, format: nil) as! NSMutableDictionary

回答2:

Believe I had this same problem, and from your code it looks like we also copied from the same example. I prepared my plist file and XCode did let my call the root an array, but my data really wasn't in an array format, it was a dictionary, and that is the format in which it was saved.

When I reloaded the plist file, NSPropertyListSerialization was smart enough to see my data was really a dictionary, and so the cast to NSMutableArray failed (BOOM!). Sure enough, when I opened the saved plist file and examined it, the XML clearly showed it had been saved as a dictionary. So, think about the data you are saving and if it really is a dictionary, change the cast to NSMutableDictionary and unpack your data using that format.

来源：https://stackoverflow.com/questions/34111323/swift-sigabrt-cast-value-of-type-nscfdictionary-to-nsmutablearray

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ios

swift

swift2