我认为这可能与过度释放有关？它一直在if (![managedObjectContext save:&error])崩溃，就像每三次调用方法一样（当我添加3个练习时）。
更新：我发现当我去往不同的例程实例时会发生这种情况。
2011-04-28 04:02:58.160 Curl[8035:707] Serious application error. Exception was caught during Core Data change processing. This is usually a bug within an observer of NSManagedObjectContextObjectsDidChangeNotification. -[__NSCFDictionary controllerWillChangeContent:]: unrecognized selector sent to instance 0x1ba1b0 with userInfo (null)
2011-04-28 04:02:58.353 Curl[8035:707] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFDictionary controllerWillChangeContent:]: unrecognized selector sent to instance 0x1ba1b0'
方法
-(void)addExercise
{
if (managedObjectContext == nil)
{
managedObjectContext = [(CurlAppDelegate *)[[UIApplication sharedApplication] delegate] managedObjectContext];
[managedObjectContext retain];
}
UIBarButtonItem *addButton = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(exerciseChooser)];
self.navigationItem.rightBarButtonItem = addButton;
[addButton release];
NSError *error = nil;
Exercise *exercise = (Exercise *)[NSEntityDescription insertNewObjectForEntityForName:@"Exercise" inManagedObjectContext:managedObjectContext];
exercise.name = selectedExercise;
NSLog(@"addExercise theSelectedRoutine: %@", theSelectedRoutine);
[theSelectedRoutine addRoutineToExercisesObject:exercise];
if (![managedObjectContext save:&error])
{
// Handle the error.
}
NSLog(@"%@", error);
NSLog(@"addExercise theSelectedRoutine: %@", theSelectedRoutine);
[self.routineTableView reloadData];
}
以下是完整代码：
@implementation RoutineDayTableViewController
@synthesize fetchedResultsController;
@synthesize exerciseChooserView;
@synthesize routineTableView;
@synthesize managedObjectContext;
@synthesize selectedExercise;
@synthesize entityArray;
@synthesize theSelectedRoutine;
- (id)initWithStyle:(UITableViewStyle)style
{
self = [super initWithStyle:style];
if (self) {
// Custom initialization
}
return self;
}
- (void)dealloc
{
NSLog(@"dealloc");
[fetchedResultsController release];
[selectedExercise release];
[managedObjectContext release];
[exerciseChooserView release];
[routineTableView release];
[entityArray release];
[theSelectedRoutine release];
[super dealloc];
}
- (void)didReceiveMemoryWarning
{
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Release any cached data, imagtaes, etc that aren't in use.
}
#pragma mark - View lifecycle
- (void)viewDidLoad
{
[super viewDidLoad];
self.routineTableView.delegate = self;
UIBarButtonItem *addButton = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(exerciseChooser)];
self.navigationItem.rightBarButtonItem = addButton;
[addButton release];
if (managedObjectContext == nil)
{
managedObjectContext = [(CurlAppDelegate *)[[UIApplication sharedApplication] delegate] managedObjectContext];
[managedObjectContext retain];
}
[self loadData];
}
-(void)loadData
{
NSFetchRequest *request = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:@"Exercise" inManagedObjectContext:managedObjectContext];
[request setEntity:entity];
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:0 inSection:0];
NSManagedObject *selectedObject = [entityArray objectAtIndex:indexPath.row];
NSLog(@"After managedObjectContext: %@", managedObjectContext);
NSError *error = nil;
NSMutableArray *mutableFetchResults = [[managedObjectContext executeFetchRequest:request error:&error] mutableCopy];
if (mutableFetchResults == nil) {
// Handle the error.
}
self.entityArray = mutableFetchResults;
[request setPredicate: [NSPredicate predicateWithFormat: @"routineExercises = %@", selectedObject]];
[mutableFetchResults release];
[request release];
}
- (void)viewDidUnload
{
NSLog(@"viewDidUnload");
[super viewDidUnload];
self.exerciseChooserView = nil;
self.routineTableView = nil;
self.fetchedResultsController = nil;
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
// Return YES for supported orientations
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
#pragma mark - Exercise Editing
-(IBAction)exerciseChooser
{
RoutineExerciseChooserViewController *routineExerciseChooserViewController = [[[RoutineExerciseChooserViewController alloc] init] autorelease];
[self.navigationController pushViewController:routineExerciseChooserViewController animated:YES];
}
-(void)addExercise
{
if (managedObjectContext == nil)
{
managedObjectContext = [(CurlAppDelegate *)[[UIApplication sharedApplication] delegate] managedObjectContext];
[managedObjectContext retain];
}
UIBarButtonItem *addButton = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(exerciseChooser)];
self.navigationItem.rightBarButtonItem = addButton;
[addButton release];
NSError *error = nil;
Exercise *exercise = (Exercise *)[NSEntityDescription insertNewObjectForEntityForName:@"Exercise" inManagedObjectContext:managedObjectContext];
exercise.name = selectedExercise;
NSLog(@"addExercise theSelectedRoutine: %@", theSelectedRoutine);
[theSelectedRoutine addRoutineToExercisesObject:exercise];
if (![managedObjectContext save:&error])
{
// Handle the error.
}
NSLog(@"%@", error);
NSLog(@"addExercise theSelectedRoutine: %@", theSelectedRoutine);
//[self.routineTableView reloadData];
}
-(void)toggleEdit
{
[self.routineTableView setEditing: !self.routineTableView.editing animated:YES];
if (self.routineTableView.editing)
[self.navigationItem.rightBarButtonItem setTitle:@"Cancel"];
else
[self.navigationItem.rightBarButtonItem setTitle:@"Edit"];
}
#pragma mark - Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return [[self.fetchedResultsController sections] count];
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
id <NSFetchedResultsSectionInfo> sectionInfo = [[self.fetchedResultsController sections] objectAtIndex:section];
return [sectionInfo numberOfObjects];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = @"Cell";
UITableViewCell *cell = [routineTableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}
Exercise *tempExercise = (Exercise *)[fetchedResultsController objectAtIndexPath:indexPath];
cell.textLabel.text = tempExercise.name;
return cell;
}
-(void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
if (editingStyle == UITableViewCellEditingStyleDelete)
{
// Delete the managed object for the given index path
NSManagedObjectContext *context = [self.fetchedResultsController managedObjectContext];
[context deleteObject:[self.fetchedResultsController objectAtIndexPath:indexPath]];
NSLog(@"fetched results : \n%@\n",[self.fetchedResultsController fetchedObjects]);
// Commit the change.
NSError *error = nil;
// Update the array and table view.
if (![managedObjectContext save:&error])
{
// Handle the error.
}
//[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:YES];
}
}
- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath
{
NSManagedObject *managedObject = [self.fetchedResultsController objectAtIndexPath:indexPath];
cell.textLabel.text = [[managedObject valueForKey:@"name"] description];
}
#pragma mark - Table view delegate
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
// Navigation logic may go here. Create and push another view controller.
[routineTableView deselectRowAtIndexPath:indexPath animated:YES];
DetailViewController *detailViewController = [[DetailViewController alloc] initWithNibName:@"DetailViewController" bundle:nil];
// ...
// Pass the selected object to the new view controller.
[self.navigationController pushViewController:detailViewController animated:YES];
[detailViewController release];
}
#pragma mark - Fetched results controller
- (NSFetchedResultsController *)fetchedResultsController
{
if (fetchedResultsController != nil)
{
return fetchedResultsController;
}
// Create the fetch request for the entity.
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
// Edit the entity name as appropriate.
NSEntityDescription *entity = [NSEntityDescription entityForName:@"Exercise" inManagedObjectContext:self.managedObjectContext];
[fetchRequest setEntity:entity];
NSLog(@"fetchedResultsController theSelectedRoutine: %@",theSelectedRoutine);
[fetchRequest setPredicate:[NSPredicate predicateWithFormat: @"ANY exerciseToRoutine == %@", theSelectedRoutine]];
// Set the batch size to a suitable number.
[fetchRequest setFetchBatchSize:20];
// Edit the sort key as appropriate.
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"name" ascending:NO];
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];
[fetchRequest setSortDescriptors:sortDescriptors];
// Edit the section name key path and cache name if appropriate.
// nil for section name key path means "no sections".
NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:self.managedObjectContext sectionNameKeyPath:nil cacheName:nil];
aFetchedResultsController.delegate = self;
self.fetchedResultsController = aFetchedResultsController;
NSError *error = nil;
if (![self.fetchedResultsController performFetch:&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. If it is not possible to recover from the error, display an alert panel that instructs the user to quit the application by pressing the Home button.
*/
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
abort();
}
return fetchedResultsController;
[aFetchedResultsController release];
[fetchRequest release];
[sortDescriptor release];
[sortDescriptors release];
}
#pragma mark - Fetched results controller delegate
- (void)controllerWillChangeContent:(NSFetchedResultsController *)controller
{
[self.routineTableView beginUpdates];
}
- (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo
atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type
{
switch(type)
{
case NSFetchedResultsChangeInsert:
[self.routineTableView insertSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeDelete:
[self.routineTableView deleteSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject
atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type
newIndexPath:(NSIndexPath *)newIndexPath
{
UITableView *tableView = self.routineTableView;
switch(type)
{
case NSFetchedResultsChangeInsert:
[tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeDelete:
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeUpdate:
[self configureCell:[tableView cellForRowAtIndexPath:indexPath] atIndexPath:indexPath];
break;
case NSFetchedResultsChangeMove:
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
[tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath]withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller
{
[self.routineTableView endUpdates];
}
@end
更新 - 这是新更新的代码：
@implementation RoutineDayTableViewController
@synthesize fetchedResultsController;
@synthesize exerciseChooserView;
@synthesize routineTableView;
@synthesize managedObjectContext;
@synthesize selectedExercise;
@synthesize theSelectedRoutine;
- (id)initWithStyle:(UITableViewStyle)style
{
self = [super initWithStyle:style];
if (self) {
// Custom initialization
}
return self;
}
- (void)dealloc
{
NSLog(@"dealloc");
[fetchedResultsController release];
[selectedExercise release];
[managedObjectContext release];
[exerciseChooserView release];
[routineTableView release];
[theSelectedRoutine release];
[super dealloc];
}
- (void)didReceiveMemoryWarning
{
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Release any cached data, imagtaes, etc that aren't in use.
}
#pragma mark - View lifecycle
- (void)viewDidLoad
{
[super viewDidLoad];
self.routineTableView.delegate = self;
UIBarButtonItem *addButton = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(exerciseChooser)];
self.navigationItem.rightBarButtonItem = addButton;
[addButton release];
if (managedObjectContext == nil)
{
managedObjectContext = [(CurlAppDelegate *)[[UIApplication sharedApplication] delegate] managedObjectContext];
[managedObjectContext retain];
}
}
- (void)viewDidUnload
{
NSLog(@"viewDidUnload");
[super viewDidUnload];
self.exerciseChooserView = nil;
self.routineTableView = nil;
self.fetchedResultsController = nil;
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
// Return YES for supported orientations
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
#pragma mark - Exercise Editing
-(IBAction)exerciseChooser
{
RoutineExerciseChooserViewController *routineExerciseChooserViewController = [[[RoutineExerciseChooserViewController alloc] init] autorelease];
[self.navigationController pushViewController:routineExerciseChooserViewController animated:YES];
}
-(void)addExercise
{
if (managedObjectContext == nil)
{
managedObjectContext = [(CurlAppDelegate *)[[UIApplication sharedApplication] delegate] managedObjectContext];
[managedObjectContext retain];
}
UIBarButtonItem *addButton = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(exerciseChooser)];
self.navigationItem.rightBarButtonItem = addButton;
[addButton release];
NSError *error = nil;
Exercise *exercise = (Exercise *)[NSEntityDescription insertNewObjectForEntityForName:@"Exercise" inManagedObjectContext:managedObjectContext];
exercise.name = self.selectedExercise;
NSLog(@"addExercise theSelectedRoutine: %@", theSelectedRoutine);
[theSelectedRoutine addRoutineToExercisesObject:exercise];
if (![fetchedResultsController.managedObjectContext save:&error])
{
// Handle the error.
}
NSLog(@"%@", error);
NSLog(@"addExercise theSelectedRoutine: %@", theSelectedRoutine);
//[self.routineTableView reloadData];
[exercise release];
[error release];
}
-(void)toggleEdit
{
[self.routineTableView setEditing: !self.routineTableView.editing animated:YES];
if (self.routineTableView.editing)
[self.navigationItem.rightBarButtonItem setTitle:@"Cancel"];
else
[self.navigationItem.rightBarButtonItem setTitle:@"Edit"];
}
#pragma mark - Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return [[self.fetchedResultsController sections] count];
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
id <NSFetchedResultsSectionInfo> sectionInfo = [[self.fetchedResultsController sections] objectAtIndex:section];
return [sectionInfo numberOfObjects];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = @"Cell";
UITableViewCell *cell = [routineTableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}
Exercise *tempExercise = (Exercise *)[fetchedResultsController objectAtIndexPath:indexPath];
cell.textLabel.text = tempExercise.name;
return cell;
}
-(void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
if (editingStyle == UITableViewCellEditingStyleDelete)
{
// Delete the managed object for the given index path
NSManagedObjectContext *context = [self.fetchedResultsController managedObjectContext];
[context deleteObject:[self.fetchedResultsController objectAtIndexPath:indexPath]];
NSLog(@"fetched results : \n%@\n",[self.fetchedResultsController fetchedObjects]);
// Commit the change.
NSError *error = nil;
// Update the array and table view.
if (![fetchedResultsController.managedObjectContext save:&error])
{
// Handle the error.
}
//[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:YES];
}
}
- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath
{
NSManagedObject *managedObject = [self.fetchedResultsController objectAtIndexPath:indexPath];
cell.textLabel.text = [[managedObject valueForKey:@"name"] description];
}
#pragma mark - Table view delegate
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
// Navigation logic may go here. Create and push another view controller.
[routineTableView deselectRowAtIndexPath:indexPath animated:YES];
DetailViewController *detailViewController = [[DetailViewController alloc] initWithNibName:@"DetailViewController" bundle:nil];
// ...
// Pass the selected object to the new view controller.
[self.navigationController pushViewController:detailViewController animated:YES];
[detailViewController release];
}
#pragma mark - Fetched results controller
- (NSFetchedResultsController *)fetchedResultsController
{
if (fetchedResultsController != nil)
{
return fetchedResultsController;
}
// Create the fetch request for the entity.
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
// Edit the entity name as appropriate.
NSEntityDescription *entity = [NSEntityDescription entityForName:@"Exercise" inManagedObjectContext:self.managedObjectContext];
[fetchRequest setEntity:entity];
NSLog(@"fetchedResultsController theSelectedRoutine: %@",theSelectedRoutine);
[fetchRequest setPredicate:[NSPredicate predicateWithFormat: @"ANY exerciseToRoutine == %@", theSelectedRoutine]];
// Set the batch size to a suitable number.
[fetchRequest setFetchBatchSize:20];
// Edit the sort key as appropriate.
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"name" ascending:NO];
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];
[fetchRequest setSortDescriptors:sortDescriptors];
// Edit the section name key path and cache name if appropriate.
// nil for section name key path means "no sections".
NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:self.managedObjectContext sectionNameKeyPath:nil cacheName:nil];
aFetchedResultsController.delegate = self;
self.fetchedResultsController = aFetchedResultsController;
NSError *error = nil;
if (![self.fetchedResultsController performFetch:&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. If it is not possible to recover from the error, display an alert panel that instructs the user to quit the application by pressing the Home button.
*/
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
abort();
}
[aFetchedResultsController release];
[fetchRequest release];
[sortDescriptor release];
[sortDescriptors release];
return fetchedResultsController;
}
#pragma mark - Fetched results controller delegate
- (void)controllerWillChangeContent:(NSFetchedResultsController *)controller
{
[self.routineTableView beginUpdates];
}
- (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo
atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type
{
switch(type)
{
case NSFetchedResultsChangeInsert:
[self.routineTableView insertSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeDelete:
[self.routineTableView deleteSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject
atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type
newIndexPath:(NSIndexPath *)newIndexPath
{
UITableView *tableView = self.routineTableView;
switch(type)
{
case NSFetchedResultsChangeInsert:
[tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeDelete:
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeUpdate:
[self configureCell:[tableView cellForRowAtIndexPath:indexPath] atIndexPath:indexPath];
break;
case NSFetchedResultsChangeMove:
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
[tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath]withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller
{
[self.routineTableView endUpdates];
}
@end
答案 0 :(得分：0)
我发现您的代码存在一些问题。
fetchedResultsController方法泄漏对NSFetchedResultsController的引用以及一些其他对象。版本必须在返回之前发生，而不是在之后。loadData在使用后为请求添加谓词？loadData甚至有什么意义？它设置entityArray，似乎没有在其他任何地方使用。在您添加fetchedResultsController之前遗留下来？tableView:commitEditingStyle:forRowAtIndexPath:会从fetchedResultsController.managedObjectContext删除一个对象，但会保存self.managedObjectContext。这应该有效，因为它们应该始终相同，但是对于两个操作使用相同的对象在语义上更正确。答案 1 :(得分：0)
您正在混合两种完全独立的访问核心数据信息的方法。对于每个tableview，您应该只有一个上下文引用和一个fetch。您至少有两个同时运行的提取和两个上下文引用。你需要挑选一个或另一个。如果您使用的是获取的结果控制器，那么您不需要viewDidLoad和loadData中的代码。
在引用属性时，您还需要使用self引用，例如您需要使用self.selectedExercise而不是selectedExercise。只有self参考表单才能自动保留和释放。