Swift核心数据不会永久存储数据(Swift core data does not store data permanently)

IPhone IT屋
问 题

I have an Entity called "Friend".. Attributes are name and age..here I have implemented bridging because NSManagedObject class for Friend has .h and .m file. My code to store data:

var err: NSError?
var delegate:AppDelegate = UIApplication.sharedApplication().delegate as AppDelegate
var friend:Friend = Friend(entity: NSEntityDescription.entityForName("Friend", inManagedObjectContext: delegate.managedObjectContext), insertIntoManagedObjectContext: delegate.managedObjectContext)
friend.friendName = "Mani"
friend.friendAge = "23"

My code to retrieve data

var result: Array = delegate.managedObjectContext.executeFetchRequest(NSFetchRequest(entityName: "Friend"), error: &err)
println("reslut \(result)")

So when I retrieve, it gives result with data..but its not stored permanently..if I quit and run the app then previous data has gone..can anyone tell me what is the issue with my code...

Here is the sample project https://github.com/rnystrom/Swift-CoreData I got it from Github..this project also has same issue..


What is the return value of the save method, is it true or false? Can you show what the output is of the following line, if you place this right before the line with the save method:

println("delegate: \(delegate); MOC: \(delegate.managedObjectContext)")

本文地址:IT屋 » Swift core data does not store data permanently

问 题


  var err:NSError? 
var delegate:AppDelegate = UIApplication.sharedApplication()。delegate as AppDelegate
var friend:Friend = Friend(entity:NSEntityDescription.entityForName(“Friend”,inManagedObjectContext:delegate.managedObjectContext),insertIntoManagedObjectContext:delegate。 managedObjectContext)
friend.friendName =“Mani”
friend.friendAge =“23”
delegate.managedObjectContext.save(& err)


  var result:Array = delegate.managedObjectContext.executeFetchRequest(NSFetchRequest(entityName:“Friend”),error:& err)
println(“reslut \(result)”)


这里是示例项目 https://github.com/rnystrom/Swift-CoreData 我从Github ...这个项目也有同样的问题..



  println (“delegate:\(delegate); MOC:\(delegate.managedObjectContext)”)

本文地址:IT屋 » Swift核心数据不会永久存储数据