使用Swift写入核心数据时出现错误代码的问题(Problems with error code when writing to core data with Swift)

使用Swift写入核心数据时出现错误代码的问题(Problems with error code when writing to core data with Swift)

我是使用Swift进行编码的新手，我正在尝试将两个文本字段写入我的核心数据文件中。 我通过在线搜索找到了我需要的大部分代码，但是我收到了一个我无法弄清楚的错误。 我已经发布了下面的整个保存功能代码但我得到一个“不能在类型'NSManagedObjectContext'的非可选值上使用可选链接”错误在以managedObjectContext开头的行上。

@IBAction func saveData(sender: AnyObject) { let entityDescription = NSEntityDescription.entityForName("MatchData", inManagedObjectContext: managedObjectContext) let matchData = MatchData(entity: entityDescription!, insertIntoManagedObjectContext: managedObjectContext) matchData.teamNumber = teamNumber.text matchData.matchNumber = matchNumber.text var error: NSError? managedObjectContext?.save(error) if let err = error { status.text = err.localizedFailureReason } else { teamNumber.text = "" matchNumber.text = "" } }

我正在使用最新版本的Xcode，我认为这个问题与Swift中的变化有关，但由于我是新手，我无法弄明白。 任何帮助调试将不胜感激。

I am new to coding with Swift and I am trying to write two text fields into my core data file. I have figured out most of the code I need by searching on line but I am getting an error that I can't figure out. I have posted the entire save function code below but I am getting a "Cannot use optional chaining on non-optional value of type 'NSManagedObjectContext'" error on the line starting with managedObjectContext.

@IBAction func saveData(sender: AnyObject) { let entityDescription = NSEntityDescription.entityForName("MatchData", inManagedObjectContext: managedObjectContext) let matchData = MatchData(entity: entityDescription!, insertIntoManagedObjectContext: managedObjectContext) matchData.teamNumber = teamNumber.text matchData.matchNumber = matchNumber.text var error: NSError? managedObjectContext?.save(error) if let err = error { status.text = err.localizedFailureReason } else { teamNumber.text = "" matchNumber.text = "" } }

I am working with the newest version of Xcode and I think the issue has something to with the changes in Swift but I can't figure it out since I am a novice. Any help debugging would be appreciated.

最满意答案

do, try, catch语句在哪里？ 如果要将对象保存到managedObjectContext ，则必须使用此语句，如下所示： do { try manaagedObjectContext.save() } catch { // handle error }

请试一试！ 希望能帮助到你

`@IBAction func saveData（sender：AnyObject）{

让entityDescription：MatchData = NSEntityDescription.insertNewObjectForEntityForName（“MatchData”，inManagedObjectContext：managedObjectContext）为！ MatchData

entityDescription.teamNumber = self.teamNumber.text entityDescription.matchNumber = self.matchNumber.text do { try managedObjectContext.save() } catch { /*Handle error*/ }

print（entityDescription）}`

Where is the do, try, catch statement? If you want to save objects to the managedObjectContext you must be use this statement like so:do { try manaagedObjectContext.save() } catch { // handle error }

Please try this out! Hope it helps

`@IBAction func saveData(sender: AnyObject) {

let entityDescription:MatchData = NSEntityDescription.insertNewObjectForEntityForName("MatchData", inManagedObjectContext: managedObjectContext) as! MatchData

entityDescription.teamNumber = self.teamNumber.text entityDescription.matchNumber = self.matchNumber.text do { try managedObjectContext.save() } catch { /*Handle error*/ }

print(entityDescription) }`