Core Data error: nil is not a legal NSManagedObjectContext parameter
Core Data error: nil is not a legal NSManagedObjectContext parameter
我完全不熟悉创建 iOS 应用程序。我必须快速创建一个表单应用程序，我可以在其中存储来自愿意填写它的人的信息。基本上只是一堆文本字段，例如姓名、邮件等。
填完表格后，我将使用这段代码存储他们的数据：
//Save action
NSEntityDescription *entityDesc = [NSEntityDescription entityForName:@"Person" inManagedObjectContext: context];
NSManagedObject *newPerson = [[NSManagedObject alloc]initWithEntity:entityDesc insertIntoManagedObjectContext:context];
//Fill in values
[newPerson setValue:self.btnPrefix.titleLabel.text forKey: @"prefix"];
[newPerson setValue:self.txtFirstName.text forKey: @"firstname"];
[newPerson setValue:self.txtLastName.text forKey: @"lastname"];
[newPerson setValue:self.txtLive.text forKey: @"country"];
[newPerson setValue:self.txtMail.text forKey: @"email"];
[newPerson setValue:self.txtPhone.text forKey: @"phonenumber"];
[newPerson setValue:self.txtLinked.text forKey: @"linkedIn"];
[newPerson setValue:self.txtAbout.text forKey: @"about"];
NSError *error;
[context save:&error];
在模拟器上执行完全没有问题。但是一旦 iPad 上的 运行 我得到这个错误：
Terminating app due to uncaught exception
'NSInvalidArgumentException', reason: '+entityForName: nil is not a
legal NSManagedObjectContext parameter searching for entity name
'Person''
调试后在第一行触发：
NSEntityDescription *entityDesc = [NSEntityDescription entityForName:@"Person" inManagedObjectContext: context];
经过更多研究，我的 Appdelegate 在设备上 运行 时包含一个 nil persistentContainer，但在虚拟设备上 运行 时它被填充。所以我猜问题是在那里，但我找不到解决它的方法。
- (void)viewDidLoad {
[super viewDidLoad];
AppDelegate *appdelegate = (AppDelegate*)[[UIApplication sharedApplication]delegate];
context = appdelegate.persistentContainer.viewContext;
}
谁能帮帮我？
对于遇到此错误的人。如果它在虚拟设备上工作但在物理设备上不工作，很可能是由于 iOS 9 和 10 之间访问核心数据的差异。
在 Xcode 8 中，AppDelegate 会自动为 iOS 10 生成数据，但如果您卡在 iOS 9 中，则需要在委托文件中添加以下代码:
@synthesize managedObjectContext = _managedObjectContext;
@synthesize managedObjectModel = _managedObjectModel;
@synthesize persistentStoreCoordinator = _persistentStoreCoordinator;
- (NSURL *) applicationDocumentsDirectory{
return [[[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask] lastObject];
}
- (NSManagedObjectModel *)managedObjectModel {
if(_managedObjectModel != nil){
return _managedObjectModel;
}
NSURL *modelURL = [[NSBundle mainBundle] URLForResource:@"StylelabsForms" withExtension:@"momd"];
_managedObjectModel = [[NSManagedObjectModel alloc] initWithContentsOfURL:modelURL];
return _managedObjectModel;
}
- (NSPersistentStoreCoordinator *) persistentStoreCoordinator{
if(_persistentStoreCoordinator != nil){
return _persistentStoreCoordinator;
}
_persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]];
NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:@"StylelabsForms.sqlite"];
NSError *error = nil;
NSString *failureReason = @"Error loading saved data";
if(![_persistentStoreCoordinator addPersistentStoreWithType: NSSQLiteStoreType configuration:nil URL: storeURL options:nil error:&error]){
NSMutableDictionary *dict = [NSMutableDictionary dictionary];
dict[NSLocalizedDescriptionKey] = @"Failed init application's saved data";
dict[NSLocalizedFailureReasonErrorKey] = failureReason;
dict[NSUnderlyingErrorKey] = error;
error = [NSError errorWithDomain:@"YOUR_ERROR_DOMAIN" code:9999 userInfo:dict];
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
abort();
}
return _persistentStoreCoordinator;
}
- (NSManagedObjectContext *) managedObjectContext {
if (_managedObjectContext != nil){
return _managedObjectContext;
}
NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator];
if(!coordinator) {
return nil;
}
_managedObjectContext = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSMainQueueConcurrencyType];
[_managedObjectContext setPersistentStoreCoordinator:coordinator];
return _managedObjectContext;
}
同时修改保存如下：
- (void)saveContext {
NSManagedObjectContext *managedObjectContext = self.managedObjectContext;
if(managedObjectContext != nil){
NSError *error = nil;
if([managedObjectContext hasChanges] && ![managedObjectContext save:&error]){
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
abort();
}
}
//For iOS 10 and above
/*
NSManagedObjectContext *context = self.persistentContainer.viewContext;
NSError *error = nil;
if ([context hasChanges] && ![context save:&error]) {
// Replace this implementation with code to handle the error appropriately.
// abort() 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.
NSLog(@"Unresolved error %@, %@", error, error.userInfo);
abort();
} */
}
private lazy var applicationDocumentsDirectory: URL = {
// 应用程序用来存储核心数据存储文件的目录。此代码使用在应用程序的文档 Application Support 目录中命名的目录。
让 urls = FileManager.default.urls（对于：.documentDirectory，在：.userDomainMask）
return 网址[urls.count-1]
}()
private lazy var managedObjectModel: NSManagedObjectModel = {
// The managed object model for the application. This property is not optional. It is a fatal error for the application not to be able to find and load its model.
let modelURL = Bundle.main.url(forResource: "CoreData", withExtension: "momd")!
return NSManagedObjectModel(contentsOf: modelURL)!
}()
private lazy var persistentStoreCoordinator: NSPersistentStoreCoordinator = {
// The persistent store coordinator for the application. This implementation creates and returns a coordinator, having added 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.
// Create the coordinator and store
let coordinator = NSPersistentStoreCoordinator(managedObjectModel: self.managedObjectModel)
let url = self.applicationDocumentsDirectory.appendingPathComponent("CoreData.sqlite")
var failureReason = "There was an error creating or loading the application's saved data."
do {
// Configure automatic migration.
let options = [ NSMigratePersistentStoresAutomaticallyOption : true, NSInferMappingModelAutomaticallyOption : true ]
try coordinator.addPersistentStore(ofType: NSSQLiteStoreType, configurationName: nil, at: url, options: options)
} catch {
// Report any error we got.
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)
// Replace this with code to handle the error appropriately.
// abort() 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.
NSLog("Unresolved error \(wrappedError), \(wrappedError.userInfo)")
abort()
}
return coordinator
}()
lazy var managedObjectContext: NSManagedObjectContext = {
var managedObjectContext: NSManagedObjectContext?
if #available(iOS 10.0, *){
managedObjectContext = self.persistentContainer.viewContext
}
else{
// Returns the managed object context for the application (which is already bound to the persistent store coordinator for the application.) This property is optional since there are legitimate error conditions that could cause the creation of the context to fail.
let coordinator = self.persistentStoreCoordinator
managedObjectContext = NSManagedObjectContext(concurrencyType: .mainQueueConcurrencyType)
managedObjectContext?.persistentStoreCoordinator = coordinator
}
return managedObjectContext!
}()
// iOS-10
@available(iOS 10.0, *)
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: "CoreData")
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)")
}
})
print("\(self.applicationDocumentsDirectory)")
return container
}()
我完全不熟悉创建 iOS 应用程序。我必须快速创建一个表单应用程序，我可以在其中存储来自愿意填写它的人的信息。基本上只是一堆文本字段，例如姓名、邮件等。
填完表格后，我将使用这段代码存储他们的数据：
//Save action
NSEntityDescription *entityDesc = [NSEntityDescription entityForName:@"Person" inManagedObjectContext: context];
NSManagedObject *newPerson = [[NSManagedObject alloc]initWithEntity:entityDesc insertIntoManagedObjectContext:context];
//Fill in values
[newPerson setValue:self.btnPrefix.titleLabel.text forKey: @"prefix"];
[newPerson setValue:self.txtFirstName.text forKey: @"firstname"];
[newPerson setValue:self.txtLastName.text forKey: @"lastname"];
[newPerson setValue:self.txtLive.text forKey: @"country"];
[newPerson setValue:self.txtMail.text forKey: @"email"];
[newPerson setValue:self.txtPhone.text forKey: @"phonenumber"];
[newPerson setValue:self.txtLinked.text forKey: @"linkedIn"];
[newPerson setValue:self.txtAbout.text forKey: @"about"];
NSError *error;
[context save:&error];
在模拟器上执行完全没有问题。但是一旦 iPad 上的 运行 我得到这个错误：
Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '+entityForName: nil is not a legal NSManagedObjectContext parameter searching for entity name 'Person''
调试后在第一行触发：
NSEntityDescription *entityDesc = [NSEntityDescription entityForName:@"Person" inManagedObjectContext: context];
经过更多研究，我的 Appdelegate 在设备上 运行 时包含一个 nil persistentContainer，但在虚拟设备上 运行 时它被填充。所以我猜问题是在那里，但我找不到解决它的方法。
- (void)viewDidLoad {
[super viewDidLoad];
AppDelegate *appdelegate = (AppDelegate*)[[UIApplication sharedApplication]delegate];
context = appdelegate.persistentContainer.viewContext;
}
谁能帮帮我？
对于遇到此错误的人。如果它在虚拟设备上工作但在物理设备上不工作，很可能是由于 iOS 9 和 10 之间访问核心数据的差异。
在 Xcode 8 中，AppDelegate 会自动为 iOS 10 生成数据，但如果您卡在 iOS 9 中，则需要在委托文件中添加以下代码:
@synthesize managedObjectContext = _managedObjectContext;
@synthesize managedObjectModel = _managedObjectModel;
@synthesize persistentStoreCoordinator = _persistentStoreCoordinator;
- (NSURL *) applicationDocumentsDirectory{
return [[[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask] lastObject];
}
- (NSManagedObjectModel *)managedObjectModel {
if(_managedObjectModel != nil){
return _managedObjectModel;
}
NSURL *modelURL = [[NSBundle mainBundle] URLForResource:@"StylelabsForms" withExtension:@"momd"];
_managedObjectModel = [[NSManagedObjectModel alloc] initWithContentsOfURL:modelURL];
return _managedObjectModel;
}
- (NSPersistentStoreCoordinator *) persistentStoreCoordinator{
if(_persistentStoreCoordinator != nil){
return _persistentStoreCoordinator;
}
_persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]];
NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:@"StylelabsForms.sqlite"];
NSError *error = nil;
NSString *failureReason = @"Error loading saved data";
if(![_persistentStoreCoordinator addPersistentStoreWithType: NSSQLiteStoreType configuration:nil URL: storeURL options:nil error:&error]){
NSMutableDictionary *dict = [NSMutableDictionary dictionary];
dict[NSLocalizedDescriptionKey] = @"Failed init application's saved data";
dict[NSLocalizedFailureReasonErrorKey] = failureReason;
dict[NSUnderlyingErrorKey] = error;
error = [NSError errorWithDomain:@"YOUR_ERROR_DOMAIN" code:9999 userInfo:dict];
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
abort();
}
return _persistentStoreCoordinator;
}
- (NSManagedObjectContext *) managedObjectContext {
if (_managedObjectContext != nil){
return _managedObjectContext;
}
NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator];
if(!coordinator) {
return nil;
}
_managedObjectContext = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSMainQueueConcurrencyType];
[_managedObjectContext setPersistentStoreCoordinator:coordinator];
return _managedObjectContext;
}
同时修改保存如下：
- (void)saveContext {
NSManagedObjectContext *managedObjectContext = self.managedObjectContext;
if(managedObjectContext != nil){
NSError *error = nil;
if([managedObjectContext hasChanges] && ![managedObjectContext save:&error]){
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
abort();
}
}
//For iOS 10 and above
/*
NSManagedObjectContext *context = self.persistentContainer.viewContext;
NSError *error = nil;
if ([context hasChanges] && ![context save:&error]) {
// Replace this implementation with code to handle the error appropriately.
// abort() 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.
NSLog(@"Unresolved error %@, %@", error, error.userInfo);
abort();
} */
}
private lazy var applicationDocumentsDirectory: URL = { // 应用程序用来存储核心数据存储文件的目录。此代码使用在应用程序的文档 Application Support 目录中命名的目录。 让 urls = FileManager.default.urls（对于：.documentDirectory，在：.userDomainMask） return 网址[urls.count-1] }()
private lazy var managedObjectModel: NSManagedObjectModel = {
// The managed object model for the application. This property is not optional. It is a fatal error for the application not to be able to find and load its model.
let modelURL = Bundle.main.url(forResource: "CoreData", withExtension: "momd")!
return NSManagedObjectModel(contentsOf: modelURL)!
}()
private lazy var persistentStoreCoordinator: NSPersistentStoreCoordinator = {
// The persistent store coordinator for the application. This implementation creates and returns a coordinator, having added 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.
// Create the coordinator and store
let coordinator = NSPersistentStoreCoordinator(managedObjectModel: self.managedObjectModel)
let url = self.applicationDocumentsDirectory.appendingPathComponent("CoreData.sqlite")
var failureReason = "There was an error creating or loading the application's saved data."
do {
// Configure automatic migration.
let options = [ NSMigratePersistentStoresAutomaticallyOption : true, NSInferMappingModelAutomaticallyOption : true ]
try coordinator.addPersistentStore(ofType: NSSQLiteStoreType, configurationName: nil, at: url, options: options)
} catch {
// Report any error we got.
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)
// Replace this with code to handle the error appropriately.
// abort() 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.
NSLog("Unresolved error \(wrappedError), \(wrappedError.userInfo)")
abort()
}
return coordinator
}()
lazy var managedObjectContext: NSManagedObjectContext = {
var managedObjectContext: NSManagedObjectContext?
if #available(iOS 10.0, *){
managedObjectContext = self.persistentContainer.viewContext
}
else{
// Returns the managed object context for the application (which is already bound to the persistent store coordinator for the application.) This property is optional since there are legitimate error conditions that could cause the creation of the context to fail.
let coordinator = self.persistentStoreCoordinator
managedObjectContext = NSManagedObjectContext(concurrencyType: .mainQueueConcurrencyType)
managedObjectContext?.persistentStoreCoordinator = coordinator
}
return managedObjectContext!
}()
// iOS-10
@available(iOS 10.0, *)
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: "CoreData")
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)")
}
})
print("\(self.applicationDocumentsDirectory)")
return container
}()