昨日、このアプリのバージョンを起動して実行しました。練習が必要で、いくつかの機能を追加したかったので、最初からやり直しました。しかし今日、エンティティに新しいオブジェクトを追加するという最も基本的なタスクをやり過ごすことはできません。保存しようとすると、この同じエラーが発生し続けます。
未解決のエラー (null)、(null)
この初期のコードのほとんどは、動作中のアプリからコピーして貼り付けたものです。それがうまくいかなかったとき、私は新しいプロジェクトを作成し、すべてのコードを再入力しました. サイコロはありません。そのため、すべての派生データを削除し、以前のバージョンのアプリをすべて削除し、シミュレーターをリセットし、Xcode を閉じて、マシンを再起動し、新しいプロジェクトを作成して、これら 4 つのクラスを再入力しました。しかし、それでも同じ臭いエラーが発生します。私のモデルには必須のプロパティはありません。ここで壁に頭をぶつけています。何か案は？私が使用しているクラスのコードは次のとおりです。
// PublisherTableViewController.h
#import <UIKit/UIKit.h>
#import "Publisher.h"
@interface PublisherTableViewController : UITableViewController <NSFetchedResultsControllerDelegate, PublisherAddDelegate>{
@private
NSFetchedResultsController *fetchedResultsController;
NSManagedObjectContext *managedObjectContext;
}
@property (strong, nonatomic) NSFetchedResultsController *fetchedResultsController;
@property (strong, nonatomic) NSManagedObjectContext *managedObjectContext;
- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath;
// PublisherTableViewController.m
#import "AddPublisherTableViewController.h"
#import "PublisherTableViewController.h"
#import "AppDelegate.h"
@interface PublisherTableViewController ()
@end
@implementation PublisherTableViewController
@synthesize fetchedResultsController, managedObjectContext;
- (id)initWithStyle:(UITableViewStyle)style
{
self = [super initWithStyle:style];
if (self) {
// Custom initialization
}
return self;
}
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([[segue identifier] isEqualToString:@"AddPublisherSegue"]) {
AddPublisherTableViewController *addPublisherController = (AddPublisherTableViewController *) [[segue destinationViewController] topViewController];
addPublisherController.delegate = self;
Publisher *newPublisher = [NSEntityDescription insertNewObjectForEntityForName:@"Publisher" inManagedObjectContext:self.managedObjectContext];
addPublisherController.publisher = newPublisher;
}
}
-(void)publisherAddViewController:(AddPublisherTableViewController *)publisherAddViewController didAddPublisher:(Publisher *)publisher
{
[self dismissModalViewControllerAnimated:YES];
}
- (void)viewDidLoad
{
if (managedObjectContext == nil)
{
managedObjectContext = [(AppDelegate *)[[UIApplication sharedApplication] delegate] managedObjectContext];
//NSLog(@"After managedObjectContext: %@", managedObjectContext);
}
NSError *error = nil;
if (![[self fetchedResultsController] performFetch:&error ]) {
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
}
[super viewDidLoad];
// Uncomment the following line to preserve selection between presentations.
// self.clearsSelectionOnViewWillAppear = NO;
// Uncomment the following line to display an Edit button in the navigation bar for this view controller.
// self.navigationItem.rightBarButtonItem = self.editButtonItem;
}
- (void)viewDidUnload
{
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
#pragma mark - Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
// Return the number of sections.
return [[self.fetchedResultsController sections]count];
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
// Return the number of rows in the section.
id<NSFetchedResultsSectionInfo> sectionInfo = [[self.fetchedResultsController sections] objectAtIndex:section];
return [sectionInfo numberOfObjects];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = @"PublisherCell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
// Configure the cell...
[self configureCell:cell atIndexPath:indexPath];
return cell;
}
-(void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath
{
Publisher *publisherForCell = (Publisher *)[fetchedResultsController objectAtIndexPath:indexPath];
cell.textLabel.text = [NSString stringWithFormat:@"%@ %@",publisherForCell.firstName, publisherForCell.lastName];
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
}
/*
// Override to support conditional editing of the table view.
- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath
{
// Return NO if you do not want the specified item to be editable.
return YES;
}
*/
/*
// Override to support editing the table view.
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
if (editingStyle == UITableViewCellEditingStyleDelete) {
// Delete the row from the data source
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
}
else if (editingStyle == UITableViewCellEditingStyleInsert) {
// Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view
}
}
*/
/*
// Override to support rearranging the table view.
- (void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)fromIndexPath toIndexPath:(NSIndexPath *)toIndexPath
{
}
*/
/*
// Override to support conditional rearranging of the table view.
- (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath
{
// Return NO if you do not want the item to be re-orderable.
return YES;
}
*/
#pragma mark - Table view delegate
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
// Navigation logic may go here. Create and push another view controller.
/*
<#DetailViewController#> *detailViewController = [[<#DetailViewController#> alloc] initWithNibName:@"<#Nib name#>" bundle:nil];
// ...
// Pass the selected object to the new view controller.
[self.navigationController pushViewController:detailViewController animated:YES];
*/
}
- (NSFetchedResultsController *)fetchedResultsController {
// Set up the fetched results controller if needed.
if (fetchedResultsController == nil) {
// Create the fetch request for the entity.
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
// Edit the entity name as appropriate.
NSEntityDescription *entity = [NSEntityDescription entityForName:@"Publisher" inManagedObjectContext:managedObjectContext];
[fetchRequest setEntity:entity];
// Edit the sort key as appropriate.
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"lastName" ascending:YES];
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:managedObjectContext sectionNameKeyPath:nil cacheName:@"Root"];
aFetchedResultsController.delegate = self;
self.fetchedResultsController = aFetchedResultsController;
// [aFetchedResultsController release];
// [fetchRequest release];
// [sortDescriptor release];
// [sortDescriptors release];
}
return fetchedResultsController;
}
/**
Delegate methods of NSFetchedResultsController to respond to additions, removals and so on.
*/
- (void)controllerWillChangeContent:(NSFetchedResultsController *)controller {
// The fetch controller is about to start sending change notifications, so prepare the table view for updates.
[self.tableView beginUpdates];
}
- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type newIndexPath:(NSIndexPath *)newIndexPath {
UITableView *tableView = self.tableView;
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:(UITableViewCell *)[tableView cellForRowAtIndexPath:indexPath] atIndexPath:indexPath];
break;
case NSFetchedResultsChangeMove:
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
[tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
- (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type {
switch(type) {
case NSFetchedResultsChangeInsert:
[self.tableView insertSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeDelete:
[self.tableView deleteSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller {
// The fetch controller has sent all current change notifications, so tell the table view to process all updates.
[self.tableView endUpdates];
}
@end
// AddPublisherTableViewController.h
#import <UIKit/UIKit.h>
#import "Publisher.h"
@protocol PublisherAddDelegate;
@interface AddPublisherTableViewController : UITableViewController{
Publisher *publisher;
UITextField *firstName;
UITextField *lastName;
// AddPublisherTableViewController.m
#import "AddPublisherTableViewController.h"
@interface AddPublisherTableViewController ()
@end
@implementation AddPublisherTableViewController
@synthesize delegate, firstName, lastName, publisher;
- (id)initWithStyle:(UITableViewStyle)style
{
self = [super initWithStyle:style];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Uncomment the following line to preserve selection between presentations.
// self.clearsSelectionOnViewWillAppear = NO;
// Uncomment the following line to display an Edit button in the navigation bar for this view controller.
// self.navigationItem.rightBarButtonItem = self.editButtonItem;
}
-(IBAction)savePublisher
{
publisher.firstName = firstName.text;
publisher.lastName = lastName.text;
NSError *error = nil;
if (![publisher.managedObjectContext save:&error]) {
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
}
[self.delegate publisherAddViewController:self didAddPublisher:publisher];
}
-(IBAction)cancel
{
if (publisher.firstName == NULL) {
[publisher.managedObjectContext deleteObject:publisher];
NSError *error = nil;
if (![publisher.managedObjectContext save:&error]) {
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
}
[self.delegate publisherAddViewController:self didAddPublisher:nil];
}else {
[self.delegate publisherAddViewController:self didAddPublisher:publisher];
}
}
- (void)viewDidUnload
{
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
@end
id<PublisherAddDelegate> delegate;
}
@property (nonatomic, strong) Publisher *publisher;
@property (nonatomic, strong) IBOutlet UITextField *firstName;
@property (nonatomic, strong) IBOutlet UITextField *lastName;
@property (nonatomic, strong) id<PublisherAddDelegate> delegate;
-(IBAction)savePublisher;
-(IBAction)cancel;
@end
@protocol PublisherAddDelegate <NSObject>
-(void)publisherAddViewController:(AddPublisherTableViewController *)publisherAddViewController didAddPublisher:(Publisher *)publisher;
@end