Question

我是swift的新手并且在使用CoreData时遇到问题：我可以保存并加载到我的CoreData存储中。但是当我从CoreData加载保存的数据时，数据已经重新排列。我不希望这种情况发生。我该如何解决这个问题？

我的代码是：

Meetings.swift

import Foundation
import CoreData

class Meetings: NSManagedObject {
    @NSManaged var meetingTimeLeft: NSNumber
    @NSManaged var title: String
    @NSManaged var date: NSDate
    @NSManaged var timeFrom: NSDate
    @NSManaged var timeTo: NSDate
    @NSManaged var timeFromActual: NSDate
    @NSManaged var timeToActual: NSDate
    @NSManaged var location: String
    @NSManaged var locationRoom: String
    @NSManaged var meetingGoals: String
    @NSManaged var purpose: String
    @NSManaged var averageHourlyCost: NSNumber
    @NSManaged var completed: NSNumber
    @NSManaged var durationActual: NSNumber
    @NSManaged var durationPlanned: NSNumber
    @NSManaged var persons: NSSet
    @NSManaged var agendas: NSSet
    @NSManaged var minutes: NSSet
    @NSManaged var relationship: NSManagedObject
    @NSManaged var startSetting: StartSetting?

}
extension Meetings {
func addPer(value: Person) {
    self.mutableSetValueForKey("persons").addObject(value)
}
func removePer(value: Person) {
    self.mutableSetValueForKey("persons").removeObject(Person)

    //self.mutableSetValueForKey("persons").addObject(value)
}


func getPer() -> [Person] {
    var persons: [Person]
    persons = self.persons.allObjects as! [Person]
    return persons
}
func addAgenda(value: AgendaItem) {
    self.mutableSetValueForKey("agendas").addObject(value)
}
func removeAgenda(value: AgendaItem) {
    self.mutableSetValueForKey("agendas").removeObject(AgendaItem)

    //self.mutableSetValueForKey("persons").addObject(value)
}


func getAgenda() -> [AgendaItem] {
    var agendas: [AgendaItem]
    agendas = self.agendas.allObjects as! [AgendaItem]
    return agendas
}
func getAgendaItem(i: Int) -> AgendaItem {
    var agendas: [AgendaItem]
    agendas = self.agendas.allObjects as! [AgendaItem]
    let agendaItem = agendas[i]
    return agendaItem
}
}

person.swift

import Foundation
import CoreData

class Person: NSManagedObject {

    @NSManaged var name: String
    @NSManaged var email: String
    @NSManaged var phone: NSNumber
    @NSManaged var title: String
    @NSManaged var company: String
    @NSManaged var photo: NSData
    @NSManaged var meeting: Meetings
}

AgendaItem.swift

import Foundation
import CoreData

class AgendaItem: NSManagedObject {
    @NSManaged var agendaItemTitle: String
    @NSManaged var presenter: String
    @NSManaged var durationPlanned: NSNumber
    @NSManaged var durationActual: NSNumber
    @NSManaged var filePresentation: NSData
    @NSManaged var fileSupporting: NSData
    @NSManaged var agendaTimeStart: NSDate
    @NSManaged var meeting: Meetings
}

保存时我喜欢这样：

internal var meetingsModels = [Meetings]()
public let managedObjectContext = (UIApplication.sharedApplication().delegate as! AppDelegate).managedObjectContext

managedObjectContext?.deleteObject(meetingsModels[meetingsIndexPassed.row]) meetingsModels.removeAtIndex(meetingsIndexPassed.row)
let entityDescription = NSEntityDescription.entityForName("Meetings", inManagedObjectContext: managedObjectContext!)
let entityDescription2 = NSEntityDescription.entityForName("Person", inManagedObjectContext: managedObjectContext!)
let entityDescription3 = NSEntityDescription.entityForName("AgendaItem", inManagedObjectContext: managedObjectContext!)


let meetings = Meetings(entity: entityDescription!, insertIntoManagedObjectContext: managedObjectContext)

meetings.title = meetingTitle_txt.text!
meetings.date = lDate
meetings.timeFrom = lStartTime
meetings.timeTo = lEndTime
meetings.location = address_txt.text!
meetings.purpose = details[0]
meetings.meetingGoals = details[1]
meetings.locationRoom = details[2]
meetings.durationPlanned = meetingsEditPassed.durationPlanned
meetings.completed = false

for var i = 0; i < personsEdit.count; i++ {
    let person = Person(entity: entityDescription2!, insertIntoManagedObjectContext: managedObjectContext)
    person.name = personsEdit[i].name
    person.email = personsEdit[i].email
    person.title = personsEdit[i].title
    person.company = personsEdit[i].company
    person.phone = personsEdit[i].phone
    meetings.addPer(person)
}
for var i = 0; i < agendaEdit.count; i++ {
    let agenda = AgendaItem(entity: entityDescription3!, insertIntoManagedObjectContext: managedObjectContext)
    agenda.agendaItemTitle = agendaEdit[i].agendaItemTitle
    //print(agendaEdit[i].agendaItemTitle)
    agenda.presenter = agendaEdit[i].presenter
    agenda.durationPlanned = agendaEdit[i].durationPlanned
    meetings.addAgenda(agenda)
}

do {
    try managedObjectContext?.save()
} catch let error1 as NSError {
    print("\(error1)")
}
meetingsModels.append(meetings)

加载时我这样做：

override func viewWillAppear(animated: Bool) {
    super.viewWillAppear(animated)
    //1
    let appDelegate =
    UIApplication.sharedApplication().delegate as! AppDelegate

    let managedContext = appDelegate.managedObjectContext!

    //2
    let fetchRequest = NSFetchRequest(entityName:"Meetings")
    //fetchRequest.sortDescriptors = nil
    //3
    let fetchedResults: [Meetings]
    do {
        try
        fetchedResults = (managedContext.executeFetchRequest(fetchRequest) as? [Meetings])!
        if let results: [Meetings] = fetchedResults {
            var temp = [Meetings]()
            var temp2 = [Meetings]()
            for tmp: Meetings in results {
                temp.append(tmp)
                if tmp.completed.boolValue {
                    temp2.append(tmp)
                }else {

                }
            }
            meetingsModels = temp
            meetingsModels2 = temp2
        } else {
        }
    } catch let error1 as NSError {
        print("could not fetch meetings: \(error1), \(error1.userInfo)")
    }



}

我希望你们中的一些人可以帮助我。

Answer 1

您的会议数据正在重新排列＆＃34;仅仅因为您的Meetings不属于任何有序关系。我无法在你身边运行你的代码。但是，我可以推荐您以下之一：

只要您想确定订单，就可以使用有序关系每次获取数据时都会保留数据。
使用 fetch requests上的sortDescriptors财产。当你创建一个，您可以为其添加sort descriptor 安排数据。

CoreData和Swift：内容被交换

1 个答案: