我正在开发一个使用core data的iOS应用程序。由于有大量的实体和需要保存的数据,因此我使用“私有上下文”方法在后台线程中保存数据,并使用块。除了一个实体外,所有实体都很好地运行。
在这个实体中,当应用程序首次启动并同步数据时,数据不会被保存,但之后如果再次同步数据,则该实体中的所有数据都将被保存。以下是我的保存数据代码:
let programAttendeeAssignArray:NSArray? = dict["data_assign"] as AnyObject? as? NSArray
for var paAssignIndex = 0; paAssignIndex < programAttendeeAssignArray?.count; paAssignIndex++ {
let programAttendeeAssignObj:NSDictionary? = programAttendeeAssignArray?.objectAtIndex(paAssignIndex) as AnyObject? as? NSDictionary
if let paAssignDict = programAttendeeAssignObj as? [String: AnyObject] {
var keyString: String = ""
if let eID = paAssignDict["id"]! as? Int {
keyString = String(eID)
}
let paAssign: Conf_speakers = Utilities.sharedInstance.getOrCreateObjectOfEntityName("Conf_speakers", key: "id", identifier: keyString, localContext: privateContext) as! Conf_speakers
if let eeid = paAssignDict["id"]! as? Int {
paAssign.id = String(eeid)
}
if let attendee_id = paAssignDict["id1"]! as? Int {
paAssign.attendee_id = String(attendee_id)
}
if let agenda_id = paAssignDict["id2"]! as? Int {
paAssign.agenda_id = String(agenda_id)
}
if let updated_at = paAssignDict["id3"]! as? String {
paAssign.updated_at = updated_at
}
}
}
let error: NSErrorPointer = nil
do {
try privateContext.save()
} catch let error1 as NSError {
error.memory = error1
} catch {
fatalError()
}
dispatch_async(dispatch_get_main_queue(), {
appDelegate.managedObjectContext.performBlock { () -> Void in
//var fds:Bool
do {
try
print("Result MSG: \(appDelegate.managedObjectContext.save())")
// fds = true
} catch _ {
//fds = false
}
}
})
appDelegate.managedObjectContext
是父上下文还是子上下文? - KrishnaCAgetOrCreateObjectOfEntityName
方法?您是如何创建上下文以及调用同步方法的,是否在 performBlock 中进行?顺便提一句,您的代码中有太多未处理的可选项。您是如何确保传递的数据不为空的呢? - ELKA