不寻常的核心数据行为 - 保存另一个对象的效果？

问题描述：

所以我想学习Swift，并且我确定我做错了什么，但我无法弄清楚可能是什么。不寻常的核心数据行为 - 保存另一个对象的效果？

我正在写一个笔记记录应用程序来帮助自己加快语言的速度。它具有表格视图（由NSArrayController填充）。点击表格视图中的一个注释会显示一个视图控制器，显示该注释的标题和正文。点击添加按钮将创建一个新的笔记管理对象，并将其传递给与用于编辑的视图控制器相同的视图控制器。

编辑笔记时，选择某些文本并按下command-l的用户可以创建一个标题等于所选文本的新笔记。

除了命令-l以外，一切都很好。这种行为是最不寻常的，我敢肯定，这是我造成的。

它是这样的：

创建注释并填写标题和正文。假设它被称为“第一”，而身体是“这是第一个，而不是第二个”。
选择一些文本（'second'）并按下command-l。这将保存当前音符，创建一个新的托管对象，填充标题（'秒'），并将其显示在视图控制器中。输入正文（'This is the second'）
保存注释。
视图控制器现在列出两个注释，因为它应该。点击第一个音符（'第一个'）现在显示第二个音符的描述。（ '这是第二个'）

下面是一些代码：

从主（表视图）控制器：

override func prepareForSegue(segue: NSStoryboardSegue, sender: AnyObject?) { 
    if segue.identifier=="CreateNote" { 
     let nextViewController = segue.destinationController as! DetailViewController 
     nextViewController.managedContext=self.managedContext 
     nextViewController.note = NSEntityDescription.insertNewObjectForEntityForName("Note", inManagedObjectContext: managedContext!) as! Note 
    } 
    else if segue.identifier=="EditNote" { 
     let theSelection = tableView.selectedRow 
     let theNote = noteArrayController?.arrangedObjects[theSelection] as! Note 
     let nextViewController = segue.destinationController as! DetailViewController 
     nextViewController.managedContext=self.managedContext 
     nextViewController.note = theNote 
    } 
}

从细节视图控制器：

import AppKit 

class DetailViewController: NSViewController, KeyNotificationProtocol { 

    @IBOutlet weak var noteTitle: NSTextField! 
    @IBOutlet var noteBody: TWTextView! 

    @IBAction func backButton(sender: AnyObject) { 
     saveNote() 
     if historyStack.isNotEmpty() { 
      note=findNoteByName(historyStack.pop()) 
      loadNote() 
     } 
    } 

    @IBAction func dismissButton(sender: AnyObject) { 
     saveNote() 
     self.dismissController(self) 
    } 
    var managedContext: NSManagedObjectContext? 
    var note: Note? 
    var noteNameToLoad: String? 
    var historyStack = Stack<String>() 

    override func viewDidLoad() { 
     super.viewDidLoad() 
     loadNote() 
     noteBody.keyDelegate = self 

     var requestArray: [KeyRequest] = [] 

     requestArray.append(KeyRequest(theFlags: [NSEventModifierFlags.CommandKeyMask], 
      theKey: "l", 
      theTag: "link", 
      theFunc: self.createLink)) 

     noteBody.keysOfInterest=requestArray 
    } 

    override func viewWillDisappear() { 
     saveNote() 
    } 

    func keypressWasReceived(keypress: KeyNotificationData) { 
     keypress.keypressRequest.funcToCall() 
    } 

    func createLink() { 
     print("create link!") 
     if(noteBody.selectedRange().length>0) { 
      saveNote() 
      if let swRange = noteBody.string?.rangeFromNSRange(noteBody.selectedRange()) { 
       let selectedText = noteBody.string!.substringWithRange(swRange) 
       let tempNote=findNoteByName(selectedText) 
       if(tempNote==nil) { 
        historyStack.push((note?.title)!) 
        self.note = (NSEntityDescription.insertNewObjectForEntityForName("Note", inManagedObjectContext: managedContext!) as! Note) 
        self.note!.title=selectedText 
        self.note!.attributedBody=NSAttributedString(string: "New note") 
        loadNote() 
       } 
       else { 
        print("note exists") 
       } 
      } 

     } 
    } 

    func saveNote() -> BooleanType { 
     if (managedContext?.hasChanges != nil) { 
      self.note?.title=noteTitle.stringValue 
      self.note?.attributedBody=noteBody.textStorage 
      var saved = false 

      do { 
       try managedContext?.save() 
       saved = true 
      } 
      catch let error as NSError { 
       print("Error saving \(error)", terminator: "") 
      } 

      return saved 
     } 
     else { 
      return true 
     } 

    } 

    func loadNote() { 
     if self.note?.title==nil { 
      self.note?.title="" 
     } 
     noteTitle.stringValue = (self.note?.title)! 

     if(self.note?.attributedBody?.length>0) { 
      noteBody.textStorage?.setAttributedString((self.note?.attributedBody)!) 
     } 
     else if(self.note?.body?.characters.count>0) { 
      noteBody.textStorage?.setAttributedString(NSAttributedString(string: (self.note?.body)!)) 
     } 
     else { 
      noteBody.textStorage?.setAttributedString(NSAttributedString(string: "")) 
     } 

    } 

    func findNoteByName(noteName: String) -> Note? { 
     let freq = NSFetchRequest(entityName: "Note") 
     freq.predicate = NSPredicate(format: "title == %@", noteName) 
     var result: [Note]=[] 
     do { 
      result = try managedContext?.executeFetchRequest(freq) as! [Note] 
     } 
     catch let theError as NSError { 
      print(theError) 
      result=[] 
     } 

     if result.count>0 { 
      return result[0] 
     } 
     else { 
      return nil 
     } 
    }  
}

创建第一个注释：

按下Command-L键后，第一个音符被保存，第二注意创建：

保存了第二个音符（点击完成）后，返回到表视图，并点击第一：

所以，试图找出这是怎么回事，我志愿加入了managedObjectContext通知。我这样做是在AppDelegate中，所有的核心数据的东西设置：

func applicationDidFinishLaunching(aNotification: NSNotification) { 
    // Insert code here to initialize your application 

    NSNotificationCenter.defaultCenter().addObserver(self, selector: "shitHappened:", name: NSManagedObjectContextObjectsDidChangeNotification, object: managedObjectContext) 

    NSNotificationCenter.defaultCenter().addObserver(self, selector: "shitHappened:", name: NSManagedObjectContextDidSaveNotification, object: managedObjectContext) 

    NSNotificationCenter.defaultCenter().addObserver(self, selector: "shitHappened:", name: NSManagedObjectContextWillSaveNotification, object: managedObjectContext) 
} 

func shitHappened(sender: AnyObject) { 
    print("-- something happened with core data --") 
    print(sender) 
}

监视我的观察者产生的输出，我没有看到的第一个音符正在更新&保存，使得主体设置到第二个！这是来自这个的数据。在这个日志数据的最后，有一个通知说First Note已被修改。哪里？！

-- something happened with core data -- 
NSConcreteNotification 0x608000045c10 {name = NSObjectsChangedInManagingContextNotification; object = <NSManagedObjectContext: 0x6180001c01e0>; userInfo = { 
    inserted = "{(\n <testwiki.Note: 0x6100000a8fa0> (entity: Note; id: 0x610000020b40 <x-coredata:///Note/tBCC61422-BDB8-44EB-A1A0-D32126C892354> ; data: {\n attributedBody = nil;\n body = nil;\n title = \"\";\n})\n)}"; 
    managedObjectContext = "<NSManagedObjectContext: 0x6180001c01e0>"; 
}} 
create link! 
-- something happened with core data -- 
NSConcreteNotification 0x61000005af40 {name = NSObjectsChangedInManagingContextNotification; object = <NSManagedObjectContext: 0x6180001c01e0>; userInfo = { 
    managedObjectContext = "<NSManagedObjectContext: 0x6180001c01e0>"; 
    updated = "{(\n <testwiki.Note: 0x6100000a8fa0> (entity: Note; id: 0x610000020b40 <x-coredata:///Note/tBCC61422-BDB8-44EB-A1A0-D32126C892354> ; data: {\n attributedBody = \"This is the first, not the second.{\\n NSFont = \\\"\\\\\\\"Helvetica 12.00 pt. P [] (0x610000247e90) fobj=0x101b11ca0, spc=3.33\\\\\\\"\\\";\\n NSParagraphStyle = \\\"Alignment 4, LineSpacing 0, ParagraphSpacing 0, ParagraphSpacingBefore 0, HeadIndent 0, TailIndent 0, FirstLineHeadIndent 0, LineHeight 0/0, LineHeightMultiple 0, LineBreakMode 0, Tabs (\\\\n 28L,\\\\n 56L,\\\\n 84L,\\\\n 112L,\\\\n 140L,\\\\n 168L,\\\\n 196L,\\\\n 224L,\\\\n 252L,\\\\n 280L,\\\\n 308L,\\\\n 336L\\\\n), DefaultTabInterval 0, Blocks (\\\\n), Lists (\\\\n), BaseWritingDirection -1, HyphenationFactor 0, TighteningForTruncation YES, HeaderLevel 0\\\";\\n}\";\n body = nil;\n title = \"The First Note\";\n})\n)}"; 
}} 
-- something happened with core data -- 
NSConcreteNotification 0x61000004dc50 {name = NSManagingContextWillSaveChangesNotification; object = <NSManagedObjectContext: 0x6180001c01e0>} 
-- something happened with core data -- 
NSConcreteNotification 0x61000024c870 {name = NSManagingContextDidSaveChangesNotification; object = <NSManagedObjectContext: 0x6180001c01e0>; userInfo = { 
    inserted = "{(\n <testwiki.Note: 0x6100000a8fa0> (entity: Note; id: 0x610000228e00 <x-coredata://18C6EA07-F369-4289-B333-53326C2B9DFE/Note/p226> ; data: {\n attributedBody = \"This is the first, not the second.{\\n NSFont = \\\"\\\\\\\"Helvetica 12.00 pt. P [] (0x610000247e90) fobj=0x101b11ca0, spc=3.33\\\\\\\"\\\";\\n NSParagraphStyle = \\\"Alignment 4, LineSpacing 0, ParagraphSpacing 0, ParagraphSpacingBefore 0, HeadIndent 0, TailIndent 0, FirstLineHeadIndent 0, LineHeight 0/0, LineHeightMultiple 0, LineBreakMode 0, Tabs (\\\\n 28L,\\\\n 56L,\\\\n 84L,\\\\n 112L,\\\\n 140L,\\\\n 168L,\\\\n 196L,\\\\n 224L,\\\\n 252L,\\\\n 280L,\\\\n 308L,\\\\n 336L\\\\n), DefaultTabInterval 0, Blocks (\\\\n), Lists (\\\\n), BaseWritingDirection -1, HyphenationFactor 0, TighteningForTruncation YES, HeaderLevel 0\\\";\\n}\";\n body = nil;\n title = \"The First Note\";\n})\n)}"; 
    updated = "{(\n)}"; 
}} 
loadNote 
Optional("second") 
Optional(New note{ 
}) 
-- something happened with core data -- 
NSConcreteNotification 0x610000053a10 {name = NSObjectsChangedInManagingContextNotification; object = <NSManagedObjectContext: 0x6180001c01e0>; userInfo = { 
    inserted = "{(\n <testwiki.Note: 0x6100000a9a80> (entity: Note; id: 0x6100002298c0 <x-coredata:///Note/tBCC61422-BDB8-44EB-A1A0-D32126C892355> ; data: {\n attributedBody = \"New note{\\n}\";\n body = nil;\n title = second;\n})\n)}"; 
    managedObjectContext = "<NSManagedObjectContext: 0x6180001c01e0>"; 
}} 
-- something happened with core data -- 
NSConcreteNotification 0x61800005cbc0 {name = NSObjectsChangedInManagingContextNotification; object = <NSManagedObjectContext: 0x6180001c01e0>; userInfo = { 
    managedObjectContext = "<NSManagedObjectContext: 0x6180001c01e0>"; 
    updated = "{(\n <testwiki.Note: 0x6100000a9a80> (entity: Note; id: 0x6100002298c0 <x-coredata:///Note/tBCC61422-BDB8-44EB-A1A0-D32126C892355> ; data: {\n attributedBody = \"This is the second.{\\n NSFont = \\\"\\\\\\\"Helvetica 12.00 pt. P [] (0x610000247e90) fobj=0x101b11ca0, spc=3.33\\\\\\\"\\\";\\n NSParagraphStyle = \\\"Alignment 4, LineSpacing 0, ParagraphSpacing 0, ParagraphSpacingBefore 0, HeadIndent 0, TailIndent 0, FirstLineHeadIndent 0, LineHeight 0/0, LineHeightMultiple 0, LineBreakMode 0, Tabs (\\\\n 28L,\\\\n 56L,\\\\n 84L,\\\\n 112L,\\\\n 140L,\\\\n 168L,\\\\n 196L,\\\\n 224L,\\\\n 252L,\\\\n 280L,\\\\n 308L,\\\\n 336L\\\\n), DefaultTabInterval 0, Blocks (\\\\n), Lists (\\\\n), BaseWritingDirection -1, HyphenationFactor 0, TighteningForTruncation YES, HeaderLevel 0\\\";\\n}\";\n body = nil;\n title = second;\n})\n)}"; 
}} 
-- something happened with core data -- 
NSConcreteNotification 0x618000240d50 {name = NSManagingContextWillSaveChangesNotification; object = <NSManagedObjectContext: 0x6180001c01e0>} 
-- something happened with core data -- 
NSConcreteNotification 0x61800005d970 {name = NSManagingContextDidSaveChangesNotification; object = <NSManagedObjectContext: 0x6180001c01e0>; userInfo = { 
    inserted = "{(\n <testwiki.Note: 0x6100000a9a80> (entity: Note; id: 0x61800003ac20 <x-coredata://18C6EA07-F369-4289-B333-53326C2B9DFE/Note/p227> ; data: {\n attributedBody = \"This is the second.{\\n NSFont = \\\"\\\\\\\"Helvetica 12.00 pt. P [] (0x610000247e90) fobj=0x101b11ca0, spc=3.33\\\\\\\"\\\";\\n NSParagraphStyle = \\\"Alignment 4, LineSpacing 0, ParagraphSpacing 0, ParagraphSpacingBefore 0, HeadIndent 0, TailIndent 0, FirstLineHeadIndent 0, LineHeight 0/0, LineHeightMultiple 0, LineBreakMode 0, Tabs (\\\\n 28L,\\\\n 56L,\\\\n 84L,\\\\n 112L,\\\\n 140L,\\\\n 168L,\\\\n 196L,\\\\n 224L,\\\\n 252L,\\\\n 280L,\\\\n 308L,\\\\n 336L\\\\n), DefaultTabInterval 0, Blocks (\\\\n), Lists (\\\\n), BaseWritingDirection -1, HyphenationFactor 0, TighteningForTruncation YES, HeaderLevel 0\\\";\\n}\";\n body = nil;\n title = second;\n})\n)}"; 
    updated = "{(\n)}"; 
}} 
-- something happened with core data -- 
NSConcreteNotification 0x618000242310 {name = NSObjectsChangedInManagingContextNotification; object = <NSManagedObjectContext: 0x6180001c01e0>; userInfo = { 
    managedObjectContext = "<NSManagedObjectContext: 0x6180001c01e0>"; 
    updated = "{(\n <testwiki.Note: 0x6100000a9a80> (entity: Note; id: 0x61800003ac20 <x-coredata://18C6EA07-F369-4289-B333-53326C2B9DFE/Note/p227> ; data: {\n attributedBody = \"This is the second.{\\n NSFont = \\\"\\\\\\\"Helvetica 12.00 pt. P [] (0x610000247e90) fobj=0x101b11ca0, spc=3.33\\\\\\\"\\\";\\n NSParagraphStyle = \\\"Alignment 4, LineSpacing 0, ParagraphSpacing 0, ParagraphSpacingBefore 0, HeadIndent 0, TailIndent 0, FirstLineHeadIndent 0, LineHeight 0/0, LineHeightMultiple 0, LineBreakMode 0, Tabs (\\\\n 28L,\\\\n 56L,\\\\n 84L,\\\\n 112L,\\\\n 140L,\\\\n 168L,\\\\n 196L,\\\\n 224L,\\\\n 252L,\\\\n 280L,\\\\n 308L,\\\\n 336L\\\\n), DefaultTabInterval 0, Blocks (\\\\n), Lists (\\\\n), BaseWritingDirection -1, HyphenationFactor 0, TighteningForTruncation YES, HeaderLevel 0\\\";\\n}\";\n body = nil;\n title = second;\n})\n)}"; 
}} 
-- something happened with core data -- 
NSConcreteNotification 0x618000242f40 {name = NSManagingContextWillSaveChangesNotification; object = <NSManagedObjectContext: 0x6180001c01e0>} 
-- something happened with core data -- 
NSConcreteNotification 0x608000046240 {name = NSManagingContextDidSaveChangesNotification; object = <NSManagedObjectContext: 0x6180001c01e0>; userInfo = { 
    inserted = "{(\n)}"; 
    updated = "{(\n <testwiki.Note: 0x6100000a9a80> (entity: Note; id: 0x61800003ac20 <x-coredata://18C6EA07-F369-4289-B333-53326C2B9DFE/Note/p227> ; data: {\n attributedBody = \"This is the second.{\\n NSFont = \\\"\\\\\\\"Helvetica 12.00 pt. P [] (0x610000247e90) fobj=0x101b11ca0, spc=3.33\\\\\\\"\\\";\\n NSParagraphStyle = \\\"Alignment 4, LineSpacing 0, ParagraphSpacing 0, ParagraphSpacingBefore 0, HeadIndent 0, TailIndent 0, FirstLineHeadIndent 0, LineHeight 0/0, LineHeightMultiple 0, LineBreakMode 0, Tabs (\\\\n 28L,\\\\n 56L,\\\\n 84L,\\\\n 112L,\\\\n 140L,\\\\n 168L,\\\\n 196L,\\\\n 224L,\\\\n 252L,\\\\n 280L,\\\\n 308L,\\\\n 336L\\\\n), DefaultTabInterval 0, Blocks (\\\\n), Lists (\\\\n), BaseWritingDirection -1, HyphenationFactor 0, TighteningForTruncation YES, HeaderLevel 0\\\";\\n}\";\n body = nil;\n title = second;\n})\n)}"; 
}} 
about to segue to editNote 
with title 
Optional("The First Note") 
Optional(This is the second.{ 
    NSFont = "\"Helvetica 12.00 pt. P [] (0x610000247e90) fobj=0x101b11ca0, spc=3.33\""; 
    NSParagraphStyle = "Alignment 4, LineSpacing 0, ParagraphSpacing 0, ParagraphSpacingBefore 0, HeadIndent 0, TailIndent 0, FirstLineHeadIndent 0, LineHeight 0/0, LineHeightMultiple 0, LineBreakMode 0, Tabs (\n 28L,\n 56L,\n 84L,\n 112L,\n 140L,\n 168L,\n 196L,\n 224L,\n 252L,\n 280L,\n 308L,\n 336L\n), DefaultTabInterval 0, Blocks (\n), Lists (\n), BaseWritingDirection -1, HyphenationFactor 0, TighteningForTruncation YES, HeaderLevel 0"; 
}) 
------------------------ 
loadNote 
Optional("The First Note") 
Optional(This is the second.{ 
    NSFont = "\"Helvetica 12.00 pt. P [] (0x610000247e90) fobj=0x101b11ca0, spc=3.33\""; 
    NSParagraphStyle = "Alignment 4, LineSpacing 0, ParagraphSpacing 0, ParagraphSpacingBefore 0, HeadIndent 0, TailIndent 0, FirstLineHeadIndent 0, LineHeight 0/0, LineHeightMultiple 0, LineBreakMode 0, Tabs (\n 28L,\n 56L,\n 84L,\n 112L,\n 140L,\n 168L,\n 196L,\n 224L,\n 252L,\n 280L,\n 308L,\n 336L\n), DefaultTabInterval 0, Blocks (\n), Lists (\n), BaseWritingDirection -1, HyphenationFactor 0, TighteningForTruncation YES, HeaderLevel 0"; 
}) 
-- something happened with core data -- 
NSConcreteNotification 0x618000241aa0 {name = NSObjectsChangedInManagingContextNotification; object = <NSManagedObjectContext: 0x6180001c01e0>; userInfo = { 
    managedObjectContext = "<NSManagedObjectContext: 0x6180001c01e0>"; 
    updated = "{(\n <testwiki.Note: 0x6100000a8fa0> (entity: Note; id: 0x610000228e00 <x-coredata://18C6EA07-F369-4289-B333-53326C2B9DFE/Note/p226> ; data: {\n attributedBody = \"This is the second.{\\n NSFont = \\\"\\\\\\\"Helvetica 12.00 pt. P [] (0x610000247e90) fobj=0x101b11ca0, spc=3.33\\\\\\\"\\\";\\n NSParagraphStyle = \\\"Alignment 4, LineSpacing 0, ParagraphSpacing 0, ParagraphSpacingBefore 0, HeadIndent 0, TailIndent 0, FirstLineHeadIndent 0, LineHeight 0/0, LineHeightMultiple 0, LineBreakMode 0, Tabs (\\\\n 28L,\\\\n 56L,\\\\n 84L,\\\\n 112L,\\\\n 140L,\\\\n 168L,\\\\n 196L,\\\\n 224L,\\\\n 252L,\\\\n 280L,\\\\n 308L,\\\\n 336L\\\\n), DefaultTabInterval 0, Blocks (\\\\n), Lists (\\\\n), BaseWritingDirection -1, HyphenationFactor 0, TighteningForTruncation YES, HeaderLevel 0\\\";\\n}\";\n body = nil;\n title = \"The First Note\";\n})\n)}"; 
}}

其他说明：我会留意的命令-1的子类NSTextView与重载的keyDown功能。

编辑：我忽略了指出，如果我创建了一长串笔记，使用command-l从一个到下一个，当我回去看时，那个链中的每个音符都会有相同的音符体在他们身上。

是问题'self.note？.attributedBody = noteBody.textStorage'？所有归属身体指向相同的文本存储。 – Willeke

就是这样！所以我不得不改变saveNote（）这一行： self.note .attributedBody = noteBody.textStorage 这些：让attributedBody = NSAttributedString（attributedString：noteBody.textStorage）？ self.note .attributedBody = belongsBody 如果你写了一个答案，我会接受它。 – Chris

答

所有的权限都指向相同的文本存储。

变化

self.note?.attributedBody=noteBody.textStorage

到

self.note?.attributedBody = NSAttributedString(attributedString: noteBody.textStorage!)

不寻常的核心数据行为 - 保存另一个对象的效果？

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