Question

我有一个iOS应用程序，它使用核心数据存储持久性数据。当我的Apple Watch伴侣应用启动时，此数据将发送到手表，如果手表中的数据不同，则会更新手表的数据。 SchoolCompanion.xdatamodeld是我的coreData模型，目标都是（iOS应用程序和Watch Extension）如何在我的iOS应用程序上处理核心数据？ 1.我创建了一个phony项目，并将其复制并粘贴到我的appDelegate.swift中 //标记：-核心数据堆栈

lazy var persistentContainer: NSPersistentContainer = {
    /*
     The persistent container for the application. This implementation
     creates and returns a container, having loaded the store for the
     application to it. This property is optional since there are legitimate
     error conditions that could cause the creation of the store to fail.
     */
    let container = NSPersistentContainer(name: "SchoolCompanion")
    container.loadPersistentStores(completionHandler: { (storeDescription, error) in
        if let error = error as NSError? {
            // Replace this implementation with code to handle the error appropriately.
            // fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.

            /*
             Typical reasons for an error here include:
             * The parent directory does not exist, cannot be created, or disallows writing.
             * The persistent store is not accessible, due to permissions or data protection when the device is locked.
             * The device is out of space.
             * The store could not be migrated to the current model version.
             Check the error message to determine what the actual problem was.
             */
            fatalError("Unresolved error \(error), \(error.userInfo)")
        }
    })
    return container
}()

// MARK: - Core Data Saving support

func saveContext () {
    let context = persistentContainer.viewContext
    if context.hasChanges {
        do {
            try context.save()
        } catch {
            // Replace this implementation with code to handle the error appropriately.
            // fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
            let nserror = error as NSError
            fatalError("Unresolved error \(nserror), \(nserror.userInfo)")
        }
    }
}

我将NSPersistentContainer名称更改为我的项目名称：“ SchoolCompanion”，核心数据模型具有相同的名称（我不知道这是否重要） 1.我创建了一个名为CoreDataHelper.swift的swift文件，以使用我的coreData进行请求获取和其他操作，例如：导入UIKit 导入CoreData

class CoreDataHelper {

    // récupérer base CoreData
    private let appDel = UIApplication.shared.delegate as! AppDelegate

    // Récupérer le contexte
    var context : NSManagedObjectContext {
        return appDel.persistentContainer.viewContext
    }

    // Sauvegarder dans CoreData
    func save() {
        appDel.saveContext()
    }   

    // ajoute le cours dans coreData
    func saveCourse(nom : String, debut: Date, fin: Date, color: Int, prof : String, local : String, day: String) {

        let course = Course(context: context)
        course.nom = nom
        course.heureDebut = debut
        course.heureFin = fin
        course.strProf = prof
        course.strLocal = local
        course.color = Int64(color)
        course.day = day
        save()
        print("cours ajouté")
    }

    // supprime le cours de CoreData
    func deleteCourse(cours: Course) {
        context.delete(cours)
        do {
            try context.save()
        } catch {
            print(error.localizedDescription)
        }
    }

    // renvoie le tableau de tout les cours confondus dans l'odre croissant
    var courses : [Course] {
        let courseRequest: NSFetchRequest<Course> = Course.fetchRequest()
        let sortDescriptor = NSSortDescriptor(key: "heureDebut", ascending: true)
        courseRequest.sortDescriptors =  [sortDescriptor]
        var coursestbl : [Course] = []
        do {
            coursestbl = try context.fetch(courseRequest)
        } catch {
            print(error.localizedDescription)
        }
        return coursestbl
    }

    // renvoie un tableau des cours du lundi
    var coursesLun : [Course] {
        let courseRequest: NSFetchRequest<Course> = Course.fetchRequest()
        let sortDescriptor = NSSortDescriptor(key: "heureDebut", ascending: true)
        courseRequest.sortDescriptors =  [sortDescriptor]
        var coursestbl : [Course] = []
        do {
            coursestbl = try context.fetch(courseRequest)
        } catch {
            print(error.localizedDescription)
        }
        var coursLundiTbl : [Course] = []
        for c in coursestbl {

            if c.day == "LUNDI" {
                coursLundiTbl.append(c)
            }
        }
        return coursLundiTbl
    }
}

这是我的iOS应用程序，可以正常使用！现在让我们谈谈我的手表应用程序，我做了什么？

在我的ExtensionDelegate中，我复制并粘贴了AppDelegate.swift的coreData方法（与上面相同）

我也创建了一个CoreDataHelper：

class CoreDataHelper {

    var context : NSManagedObjectContext {
        return ExtensionDelegate().persistentContainer.viewContext
    }

    // Sauvegarder dans CoreData
    func save() {
        ExtensionDelegate().saveContext()
    }

    // ajoute le cours dans coreData
    func saveCourse(cours : Course) {

        let course = Course(context: context)
        course.nom = cours.nom
        course.heureDebut = cours.heureDebut
        course.color = cours.color
        course.day = cours.day
        //save()
        do {
        try context.save()
        print("context saved successfully")
        } catch {
            print(error.localizedDescription)
        }
    }

    // ajoute le cours dans coreData
    func saveCourse(nom : String, debut: Date, color: Int, day: String) {

        let course = Course(context: context)
        course.nom = nom
        course.heureDebut = debut
        course.color = Int64(color)
        course.day = day
        save()
        print("cours ajouté")
    }

    // supprime le cours de CoreData
    func deleteCourse(cours: Course) {
        context.delete(cours)
        do {
            try context.save()
        } catch {
            print(error.localizedDescription)
        }
    }

    // renvoie le tableau de tout les cours confondus dans l'odre croissant
    var courses : [Course] {
        get {
            let courseRequest: NSFetchRequest<Course> = Course.fetchRequest()
            let sortDescriptor = NSSortDescriptor(key: "heureDebut", ascending: true)
            courseRequest.sortDescriptors =  [sortDescriptor]
            var coursestbl : [Course] = []
            do {
                coursestbl = try context.fetch(courseRequest)
            } catch {
                print(error.localizedDescription)
            }
            return coursestbl
        }
    }
}

因此，当手表应用启动时，它将尝试更新coreData的Apple Watch数据，保存成功，但获取请求始终返回空数组。我要扣除coreData在手表上不起作用，但是为什么呢？

也许这可以帮助？

How do I add Core Data stack to WatchKit app

Core Data support in page based app

Git存储库链接：https://github.com/CedricLnx/School-Companion

如何为手表应用添加Core Data支持？

0 个答案: