[英]Copy core data file model from Objective-C app to brand new Swift 3 project
[英]Importing Core Data database to new project
我正在将另一个项目中的应用程序从Objective-C重写到Swift,但是导入核心数据数据库时遇到问题(获取请求返回空结果),该问题在以前的项目中由MagicalRecord处理。
这是我在做什么:
将数据库模型文件复制到新项目。
在构建阶段,将该模型文件添加到“编译源和副本捆绑资源”中。
将实体代码生成语言从objc更改为在模型文件内部快速转换。
创建NSManagedObject子类
我检查过的事情:
这是我初始化堆栈的方式(当然,由于已知原因我更改了这里的字符串,它们在项目中有效):
lazy var applicationDocumentsDirectory: URL = {
let urls = FileManager.default.urls(for: .applicationSupportDirectory, in: .userDomainMask)
var applicationDocumentsDirectoryRaw = urls[urls.count-1]
applicationDocumentsDirectoryRaw.appendPathComponent("App_Name", isDirectory: true)
return applicationDocumentsDirectoryRaw
}()
lazy var managedObjectModel: NSManagedObjectModel = {
let modelURL = Bundle.main.url(forResource: "Model_Name", withExtension: "momd")!
return NSManagedObjectModel.init(contentsOf: modelURL)!
}()
lazy var persistentStoreCoordinator: NSPersistentStoreCoordinator = {
let coordinator = NSPersistentStoreCoordinator(managedObjectModel: self.managedObjectModel)
let url = self.applicationDocumentsDirectory.appendingPathComponent("CoreDataStore.sqlite")
var failureReason = "There was an error creating or loading the application's saved data."
do {
try coordinator.addPersistentStore(ofType: NSSQLiteStoreType, configurationName: nil, at: url, options: [NSMigratePersistentStoresAutomaticallyOption: true])
} catch {
var dict = [String: AnyObject]()
dict[NSLocalizedDescriptionKey] = "Failed to initialize the application's saved data" as AnyObject?
dict[NSLocalizedFailureReasonErrorKey] = failureReason as AnyObject?
dict[NSUnderlyingErrorKey] = error as NSError
let wrappedError = NSError(domain: "YOUR_ERROR_DOMAIN", code: 9999, userInfo: dict)
NSLog("Unresolved error \(wrappedError), \(wrappedError.userInfo)")
abort()
}
return coordinator
}()
lazy var managedObjectContext: NSManagedObjectContext = {
let coordinator = self.persistentStoreCoordinator
var managedObjectContext = NSManagedObjectContext(concurrencyType: .mainQueueConcurrencyType)
managedObjectContext.persistentStoreCoordinator = coordinator
return managedObjectContext
}()
PersistentStore的URL 没有被当前和以前的项目相同。
我以为是,但不是。 MagicalRecord的方法之一NSPersistentStore.MR_defaultLocalStoreUrl
返回了无效的NSURL。
对于子孙后代-通过Xcode设备管理器下载应用程序的IPA,并手动找到其URL!
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