小编Joh*_*son的帖子

我正在使用核心数据来保存vc1中的类别,并希望将列表属性添加到vc2中的列表中.我的数据模型是许多列表属性的一个类别.

我在vc1中添加了这样的类别:

func createNewCategory() {
    var category: NSManagedObject! = NSEntityDescription.insertNewObjectForEntityForName("Category", inManagedObjectContext: self.context) as NSManagedObject
    category.setValue(self.categoryTextField.text, forKey: "name")

    var error: NSError? = nil
    self.context.save(&error)
}

在vc2中设置数据:

func setupCoreData() {
    var appDelegate: AppDelegate = (UIApplication.sharedApplication()).delegate as AppDelegate
    self.context = appDelegate.managedObjectContext!

    var request: NSFetchRequest = NSFetchRequest(entityName: "Category")
    if (self.context.executeFetchRequest(request, error: nil)) {
        var error: NSError? = nil
        self.listData = self.context.executeFetchRequest(request, error: &error)
        self.managedObject = self.listData.objectAtIndex(0) as NSManagedObject
    }
}

它在最后一行崩溃:self.managedObject = ...说:

CoreData: error: Failed to call designated initializer on NSManagedObject …