println 错误... EXC_BREAKPOINT（代码=EXC_I386_BPT，子代码=0x0）swift

Question

我一直在努力寻找解决该错误的方法..但不能并且需要你的帮助..

我正在使用核心数据，特别是 NSFetchResultsController 来填充 table 视图。我有 2 个 VC，第一个（MyViewController）具有 table 视图，第二个（AddToDoViewController）用于添加新单元格。第二个是从第一个导航栏按钮调用的模态 segue。

当我在第二个视图控制器上单击保存时，应用程序崩溃，没有错误描述，只有那一行作为指示：EXC_BREAKPOINT (code=EXC_I386_BPT, subcode=0x0)

如果我在第一个 "UIAlertView" 之前删除 println() 中的 'error = (error)' 应用程序不会再崩溃...无法理解为什么...感谢帮助，谢谢！

导入 UIKit 导入核心数据进口基金会

类 AddToDoViewController: UIViewController, UITextFieldDelegate {

@IBOutlet weak var textField: UITextField!
var managedObjectContext : NSManagedObjectContext?

override func viewDidLoad() {
    super.viewDidLoad()

    // Do any additional setup after loading the view.

}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}


@IBAction func save(sender: UIBarButtonItem) {

    let name: String? = self.textField.text

    if name != "" {
        var itemEntity = NSEntityDescription.entityForName("Item", inManagedObjectContext: self.managedObjectContext!)

        if let entity = itemEntity {
            var record = NSManagedObject(entity: entity, insertIntoManagedObjectContext: self.managedObjectContext)
            var date = NSDate()
            record.setValue(name, forKey: "name")
            record.setValue(date, forKey: "createdAt")
            println("record inserted in managed context")
        }

        var saveError: NSError? = NSError()
        var success: Bool = self.managedObjectContext!.save(&saveError)

        if let anError = saveError {
            println("unable to save record & success = \(success) & error = \(anError)")

            UIAlertView(title: "Warning!", message: "Your to-do item could not be saved", delegate: nil, cancelButtonTitle: "OK", otherButtonTitles: "").show()

        } else {
            println("Save success with no error")
            self.dismissViewControllerAnimated(true, completion: nil)
        }

    } else {
        UIAlertView(title: "Warning!", message: "Your to-do item needs a name!", delegate: nil, cancelButtonTitle: "OK", otherButtonTitles: "").show()
    }

}

@IBAction func cancel(sender: AnyObject) {
    self.dismissViewControllerAnimated(true, completion: nil)
}


/*
// MARK: - Navigation

// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    // Get the new view controller using segue.destinationViewController.
    // Pass the selected object to the new view controller.
}
*/

}

Answer 1

当然，var saveError 永远不会是 nil。您已在此处实例化它："var saveError: NSError? = NSError()" 要么像这样声明它 "var saveError: NSError?" 要么把这部分放在一起。

println 错误... EXC_BREAKPOINT（代码=EXC_I386_BPT，子代码=0x0）swift

Error in println... EXC_BREAKPOINT (code=EXC_I386_BPT, subcode=0x0) swift

swift