我正在重置我在 coreData 中的数据,下面是我在 CoreData 中重置我的数据的代码
- (void) resetApplicationModel
{
__managedObjectContext = nil;
__managedObjectModel = nil;
__persistentStoreCoordinator = nil;
_allPageViewController.controller = nil;
NSError *error;
NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:@"abc.sqlite"];
if ([[self.managedObjectContext persistentStoreCoordinator] removePersistentStore:[[[self.managedObjectContext persistentStoreCoordinator] persistentStores] lastObject] error:&error])
{
// remove the file containing the data
if([[NSFileManager defaultManager] removeItemAtURL:storeURL error:&error])
{
//recreate the store like in the appDelegate method
if([self.persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeURL options:nil error:&error] == nil)
{
NSLog( @"could not create new persistent store at %@ - %@", [storeURL absoluteString], [error localizedDescription]);
}
}
else
{
NSLog( @"could not remove the store URL at %@ - %@", [storeURL absoluteString], [error localizedDescription]);
}
}
else
{
NSLog( @"could not remove persistent store - %@", [error localizedDescription]);
}
}
此代码正常工作我表中的所有数据都被删除。现在,当我尝试再次添加时,出现此错误
CoreData: error: Serious application error. An exception was caught from the delegate of NSFetchedResultsController during a call to -controllerDidChangeContent:. attempt to insert row 3 into section 0, but there are only 0 rows in section 0 after the update with userInfo (null)
我试图调试这个问题,我才知道我的数据库是空的。但我不明白为什么。如果我在不重置的情况下运行该应用程序,则一切正常。
所以请帮帮我。
这是我关于 FRC 代表的代码
- (void)controllerWillChangeContent:(NSFetchedResultsController *)controller
{
[m_tableView beginUpdates];
}
- (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo
atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type
{
if (!m_userDrivenModelChange)
{
switch(type)
{
case NSFetchedResultsChangeInsert:
[m_tableView insertSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeDelete:
[m_tableView deleteSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
}
- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject
atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type
newIndexPath:(NSIndexPath *)newIndexPath
{
switch(type) {
case NSFetchedResultsChangeInsert:
[m_tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationLeft];
break;
case NSFetchedResultsChangeDelete:
[m_tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeMove:
[m_tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
[m_tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath]withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller
{
[m_tableView endUpdates];
}
应用程序在 [m_tableView endUpdates] 行崩溃。
问候兰吉特