如何在Swift中的Core Data中保存多个项目

Question

I have the following function using Core Data to segue the results to the ScoreTableViewController:

func showScore(){

    let appDelegate = UIApplication.sharedApplication().delegate as! AppDelegate
    let gameResult = NSEntityDescription.insertNewObjectForEntityForName("SaveGame", inManagedObjectContext: appDelegate.managedObjectContext) as! ScoreHistory

    gameResult.datePlayed = self.dateToday
    gameResult.totalScore = self.scorepassed
    gameResult.totalAnswered = self.numberofquestions
    gameResult.totalDuration = self.totalduration
    gameResult.gameStatus = self.gameStatus

    self.performSegueWithIdentifier("scoreListSegue", sender: self)
}

I am able to show the Score in ScoreTableViewController thru:

override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCellWithIdentifier("Cell")! as UITableViewCell

    if let game = fetchedResultsController!.objectAtIndexPath(indexPath) as? ScoreHistory {
        cell.textLabel?.text = "Date: \(game.datePlayed!) | Score: \(game.totalScore!)/\(game.totalAnswered!) | \(game.totalDuration!) | \(game.gameStatus!)"

    }
    return cell
}

However, when I restart the app, the DATA IS NO LONGER THERE.

I have seen this code to save the “totalScore” data:

func saveScore(saveTotalScore: String){

    let appDelegate = UIApplication.sharedApplication().delegate as! AppDelegate
    let managedContext = appDelegate.managedObjectContext
    let entity = NSEntityDescription.entityForName("SaveGame", inManagedObjectContext: managedContext)
    let totalScore = NSManagedObject(entity: entity!, insertIntoManagedObjectContext: managedContext)
    totalScore.setValue(saveTotalScore, forKey: "totalScore")

    do {
        try managedContext.save()
        scoreData.append(totalScore)
    }
    catch {
        print("error")
    }
}

However, how do I SAVE ALL of the data that I need? (For instance: datePlayed, totalScore, totalAnswered, totalDuration, and gameStatus)

Answer 1

The easiest way is to do something like this after you have populated the gameResult object with everything you wanted to save.

 do {
   try appDelegate.managedObjectContext.save()
 } catch {
    fatalError("Failure to save context: \(error)")
 }

You need to call save on the appropriate managedObjectContext in order for the object to be stored.

Link to the apple docs that explains it here