如何在Swift中的Core Data中保存多個項目

Question

我有以下使用Core Data將結果隔離到ScoreTableViewController的函數：

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)
}

我可以通過以下方式在ScoreTableViewController中顯示分數：

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
}

但是，當我重新啟動應用程序時，數據就不再存在了。

我看過以下代碼來保存“ totalScore”數據：

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")
    }
}

但是，如何保存所需的所有數據？ （例如：datePlayed，totalScore，totalAnswered，totalDuration和gameStatus）

Answer 1

最簡單的方法是在將要保存的所有內容填充到gameResult對象之后，執行類似的gameResult 。

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

您需要在適當的managedObjectContext上調用save以便存儲對象。

鏈接到在這里說明的蘋果文檔