我有我的CoreDataManager类和初始化核心数据对象。
但是,当下面的代码运行时,它将引发错误并导致应用程序崩溃。
NSPersistentStoreCoordinator没有持久性存储(无法打开)
当我调试代码时,它表明persistentStore对象实际上为零。
这是我的CoreDataManager.m
文件
+ (id)sharedInstance {
static CoreDataManager *instance_ = nil;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
instance_ = [[self alloc] init];
});
return instance_;
}
- (NSManagedObjectContext *)managedObjectContext {
if (managedObjectContext != nil) {
return managedObjectContext;
}
NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator];
if (coordinator != nil) {
managedObjectContext = [NSManagedObjectContext new];
[managedObjectContext setPersistentStoreCoordinator: coordinator];
}
return managedObjectContext;
}
- (NSManagedObjectModel *)managedObjectModel {
if (managedObjectModel != nil) {
return managedObjectModel;
}
managedObjectModel = [[NSManagedObjectModel alloc]initWithContentsOfURL:[[NSBundle mainBundle] URLForResource:@"AppTutor" withExtension:@"momd"]];
return managedObjectModel;
}
- (NSURL *)applicationDocumentsDirectory
{
return [[[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask] lastObject];
}
- (NSPersistentStoreCoordinator *)persistentStoreCoordinator {
if (persistentStoreCoordinator != nil) {
return persistentStoreCoordinator;
}
NSString *documentsStorePath =
[[[self applicationDocumentsDirectory] path] stringByAppendingPathComponent:@"AppTutor.sqlite"];
// if the expected store doesn't exist, copy the default store
if (![[NSFileManager defaultManager] fileExistsAtPath:documentsStorePath]) {
NSString *defaultStorePath = [[NSBundle mainBundle] pathForResource:@"AppTutor" ofType:@"sqlite"];
if (defaultStorePath) {
[[NSFileManager defaultManager] copyItemAtPath:defaultStorePath toPath:documentsStorePath error:NULL];
}
}
persistentStoreCoordinator =
[[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]];
// add the default store to our coordinator
NSError *error;
NSURL *defaultStoreURL = [NSURL fileURLWithPath:documentsStorePath];
NSPersistentStore *store = [persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType
configuration:nil
URL:defaultStoreURL
options:nil
error:&error];
if (store == nil) {
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
}
// setup and add the user's store to our coordinator
NSURL *userStoreURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:@"AppTutor.sqlite"];
if (![persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType
configuration:nil
URL:userStoreURL
options:nil
error:&error]) {
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
}
return persistentStoreCoordinator;
}
最佳答案
您可以尝试将这些选项添加到addPersistentStoreWithType
函数吗?
NSMutableDictionary *options = [[NSMutableDictionary alloc] init];
[options setObject:[NSNumber numberWithBool:YES] forKey:NSMigratePersistentStoresAutomaticallyOption];
[options setObject:[NSNumber numberWithBool:YES] forKey:NSInferMappingModelAutomaticallyOption];
[persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType
configuration:nil
URL:userStoreURL
options:options
error:&error]
关于ios - NSPersistentStoreCoordinator没有持久性存储(无法打开),我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/40765989/