如何将多个对象保存到关系实体中。 Xcode中

我有数组中的数据。 我将它们加载到UITableViewController中，当我选择一个单元格时，来自单元格的数据会添加到Array中。 然后我想在Core Data中保存Array中的数据，但我无法做到。 我只能保存一个文件。 我该怎么做？

@IBAction func saveAllData(sender: UIBarButtonItem) { var index = tableView.indexPathForSelectedRow()! var row = tableView.indexPathForSelectedRow()!.row var playlistEntity = NSEntityDescription.insertNewObjectForEntityForName("Playlist", inManagedObjectContext: managedObjectContext) as! NSManagedObject var songEntity = NSEntityDescription.insertNewObjectForEntityForName("Song", inManagedObjectContext: managedObjectContext) as! NSManagedObject if boolForName == true { playlistEntity.setValue(currentSong, forKey: "namePlaylist") boolForName = false } for item in arraySong { println(item) songEntity.setValue(item, forKey: "dataSong") } playlistEntity.setValue(NSSet(object: songEntity), forKey: "song") managedObjectContext.save(nil) println("play list \(playlistEntity)") println("song entity \(songEntity)") var storyboard = UIStoryboard(name: "Main", bundle: NSBundle.mainBundle()) var navi = storyboard.instantiateViewControllerWithIdentifier("navi") as! UINavigationController presentViewController(navi, animated: true, completion: nil) } 

更新了我重新制作了这段代码，但它保存了相同的内容。

 @IBAction func saveAllData(sender: UIBarButtonItem) { var index = tableView.indexPathForSelectedRow()! var row = tableView.indexPathForSelectedRow()!.row println(index) println(currentArray[row]) var currentFile = currentArray[row] var playlistEntity = NSEntityDescription.insertNewObjectForEntityForName("Playlist", inManagedObjectContext: managedObjectContext) as! NSManagedObject var songEntity = NSEntityDescription.insertNewObjectForEntityForName("Song", inManagedObjectContext: managedObjectContext) as! NSManagedObject if boolForName == true { playlistEntity.setValue(currentSong, forKey: "namePlaylist") boolForName = false } for item in arraySong { songEntity.setValue(item, forKey: "dataSong") playlistEntity.setValue(NSSet(object: songEntity), forKey: "song") managedObjectContext.save(nil) println(songEntity) } managedObjectContext.save(nil) println("play list \(playlistEntity)") println("song entity \(songEntity)") var storyboard = UIStoryboard(name: "Main", bundle: NSBundle.mainBundle()) var navi = storyboard.instantiateViewControllerWithIdentifier("navi") as! UINavigationController presentViewController(navi, animated: true, completion: nil) } 

UPDATE

 var arraySong = [String]() // MARK: IBAction func @IBAction func saveAllData(sender: UIBarButtonItem) { var row = tableView.indexPathForSelectedRow()!.row var currentFile = currentArray[row] var playlistEntity = NSEntityDescription.insertNewObjectForEntityForName("Playlist", inManagedObjectContext: managedObjectContext) as! NSManagedObject var songEntity = NSEntityDescription.insertNewObjectForEntityForName("Song", inManagedObjectContext: managedObjectContext) as! NSManagedObject if boolForName == true { playlistEntity.setValue(currentSong, forKey: "namePlaylist") boolForName = false } for item in arraySong { songEntity.setValue(item, forKey: "dataSong") playlistEntity.setValue(NSSet(object: songEntity), forKey: "song") managedObjectContext.save(nil) println("play list \(playlistEntity)") println("song entity \(songEntity)") } managedObjectContext.save(nil) var storyboard = UIStoryboard(name: "Main", bundle: NSBundle.mainBundle()) var navi = storyboard.instantiateViewControllerWithIdentifier("navi") as! UINavigationController presentViewController(navi, animated: true, completion: nil) } 

我尝试了但是我只保存了数组中的最后一个对象。

  for var x = 0; x < arraySong.count; x++ { var item = arraySong[x] println(item) songEntity.setValue(item, forKey: "dataSong") playlistEntity.setValue(NSSet(object: songEntity), forKey: "song") managedObjectContext.save(nil) // println("play list \(playlistEntity)") // println("song entity \(songEntity)") println(songEntity) } 

所以我将UITableViewController中的歌曲添加到数组中。

  override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) { tableView.selectRowAtIndexPath(indexPath, animated: true, scrollPosition: UITableViewScrollPosition.None) var row = tableView.indexPathForSelectedRow()!.row var song = currentArray[row] arraySong.append(song) var cell = tableView.cellForRowAtIndexPath(indexPath)! cell.accessoryType = UITableViewCellAccessoryType.Checkmark } 

更新2

我尝试过这个

 for var x = 0; x < arraySong.count; x++ { var item = arraySong[x] println(item) var songEntity = NSEntityDescription.insertNewObjectForEntityForName("Song", inManagedObjectContext: managedObjectContext) as! NSManagedObject songEntity.setValue(item, forKey: "dataSong") playlistEntity.setValue(NSSet(object: songEntity), forKey: "song") managedObjectContext.save(nil) // println("play list \(playlistEntity)") // println("song entity \(songEntity)") println(songEntity) } 

更新3仍然我尝试了这种方法，但我只保存了我选择的第一个对象。 有什么方法吗？ 如何为特定播放列表（另一个实体）保存多首歌曲（对象）？

  override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) { tableView.selectRowAtIndexPath(indexPath, animated: true, scrollPosition: UITableViewScrollPosition.None) var indexPath = tableView.indexPathForSelectedRow()! var row = tableView.indexPathForSelectedRow()!.row var song = currentArray[row] // arraySong.append(song) var cell = tableView.cellForRowAtIndexPath(indexPath)! cell.accessoryType = UITableViewCellAccessoryType.Checkmark var playlistEntity = NSEntityDescription.insertNewObjectForEntityForName("Playlist", inManagedObjectContext: managedObjectContext) as! NSManagedObject var songEntity = NSEntityDescription.insertNewObjectForEntityForName("Song", inManagedObjectContext: managedObjectContext) as! NSManagedObject if boolForName == true { playlistEntity.setValue(currentSong, forKey: "namePlaylist") boolForName = false } songEntity.setValue(song, forKey: "dataSong") playlistEntity.setValue(NSSet(object: songEntity), forKey: "song") managedObjectContext.save(nil) println(songEntity) } 

我还是试过了。

  override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) { tableView.selectRowAtIndexPath(indexPath, animated: true, scrollPosition: UITableViewScrollPosition.None) var indexPath = tableView.indexPathForSelectedRow()! var row = tableView.indexPathForSelectedRow()!.row var song = currentArray[row] arraySong.append(song) var cell = tableView.cellForRowAtIndexPath(indexPath)! cell.accessoryType = UITableViewCellAccessoryType.Checkmark let playlistEntity = NSEntityDescription.insertNewObjectForEntityForName("Playlist", inManagedObjectContext: managedObjectContext) as! NSManagedObject let songEntity = NSEntityDescription.insertNewObjectForEntityForName("Song", inManagedObjectContext: managedObjectContext) as! NSManagedObject if boolForName == true { playlistEntity.setValue(currentSong, forKey: "namePlaylist") boolForName = false } for var digit = 0; digit < arraySong.count; digit++ { var savedSong = arraySong[digit] songEntity.setValue(savedSong, forKey: "dataSong") playlistEntity.setValue(Set(arrayLiteral: songEntity), forKey: "song") managedObjectContext.save(nil) } 

的entites

 import Foundation import CoreData @objc(Playlist) class Playlist: NSManagedObject { @NSManaged var namePlaylist: String @NSManaged var song: NSSet } import Foundation import CoreData @objc(Song) class Song: NSManagedObject { @NSManaged var dataSong: String @NSManaged var playlist: Playlist } 

核心数据中的关系实体

更新4我试过，但这种方法保存了几个新的播放列表。 我就知道。 谁能以编程方式向我展示它？

  override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) { tableView.selectRowAtIndexPath(indexPath, animated: true, scrollPosition: UITableViewScrollPosition.None) // let indexP = tableView.indexPathForSelectedRow()! let row = tableView.indexPathForSelectedRow()!.row var song = currentArray[row] var cell = tableView.cellForRowAtIndexPath(indexPath)! cell.accessoryType = UITableViewCellAccessoryType.Checkmark let playlistEntity = NSEntityDescription.insertNewObjectForEntityForName("Playlist", inManagedObjectContext: managedObjectContext) as! NSManagedObject let songEntity = NSEntityDescription.insertNewObjectForEntityForName("Song", inManagedObjectContext: managedObjectContext) as! NSManagedObject songEntity.setValue(song, forKey: "dataSong") playlistEntity.setValue(Set(arrayLiteral: songEntity), forKey: "song") println(songEntity) println(playlistEntity) managedObjectContext.save(nil) } 

Answer 1

每次选择一行时，您都会创建一个新播放列表和一首新歌曲。 在选择歌曲之前创建播放列表，仅在添加新歌曲时更新关系。