只是一个警告，这是我的第一个问题，对我温柔。
我有一个符合NSFetchedResultsControllerDelegate协议的UITableViewController。一切都很完美。我想将其更改为UIViewController，以便能够向视图添加更多内容而不仅仅是tableview。我创建了tableView属性并设置了委托和数据源。一切正常，除了没有调用FRC委托方法并且表没有更新。插入，编辑和删除存储在数据库中，但是当我在上下文中更改某些内容时，表不会更新。
所有代码都是使用获取结果控制器的基本模板代码。当它在行中设置委托时：
aFetchedResultsController.delegate = self;
应该正确设置委托，但事实并非如此。同样，我做的唯一更改是从UITableViewController中删除单词Table。它适用于UITableViewController，但不适用于UIViewController。我对此进行了广泛的研究，但没有找到答案。
感谢。
以下是一些代码：
#import <UIKit/UIKit.h>
#import <CoreData/CoreData.h>
.
.
.
@class NowWhatDetailViewController;
@class Event;
@interface NowWhatMasterViewController : UITableViewController <NSFetchedResultsControllerDelegate, ChangeDateViewControllerDelgate, EditEventViewControllerDelgate, PasswordViewControllerDelegate,
UITableViewDelegate, UITableViewDataSource> {
NSMutableArray *saveButtonItems;
IBOutlet UILabel *nextEventLabel;
IBOutlet UILabel *timeToNextEventLabel;
}
@property (strong, nonatomic) NowWhatDetailViewController *detailViewController;
@property (strong, nonatomic) NSFetchedResultsController *fetchedResultsController;
@property (strong, nonatomic) NSManagedObjectContext *managedObjectContext;
@property (nonatomic, weak) id <ChangeDateViewControllerDelgate> delegate;
@property (nonatomic, retain) IBOutlet UITableView *tableView;
.
.
.
@end
And the important sections of NowWhatMasterViewController.m
#import "NowWhatMasterViewController.h"
@interface NowWhatMasterViewController () {
}
@end
@implementation NowWhatMasterViewController {
Event *lastEditedEvent;
}
- (void)viewDidLoad
{
[super viewDidLoad];
[self performFetch];
[[self.splitViewController.viewControllers lastObject] topViewController];
self.detailViewController.viewNSDate = self.viewNSDate;
self.detailViewController.viewDate = self.viewDate;
self.detailViewController.viewSchedule = self.viewSchedule;
self.detailViewController.managedObjectContext = self.managedObjectContext;
self.detailViewController.fetchedResultsControllerDetail = self.fetchedResultsController;
[self.detailViewController updateDetailView];
// show the bottom toolbar
[self.navigationController setToolbarHidden:NO];
saveButtonItems = [self.toolbarItems mutableCopy];
nextEventLabel.text = @"next event";
timeToNextEventLabel.text = @"starts in ## minutes";
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
self.fetchedResultsController = nil;
}
- (void)viewDidUnload {
self.fetchedResultsController = nil;
}
#pragma mark - Table View
/*
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return [dayEvents count];
}
*/
- (void)tableView:(UITableView *)tableView accessoryButtonTappedForRowWithIndexPath:(NSIndexPath *)indexPath
{
Event *event = [self.fetchedResultsController objectAtIndexPath:indexPath];
[self performSegueWithIdentifier:@"EditEvent" sender:event];
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
id <NSFetchedResultsSectionInfo> sectionInfo = [self.fetchedResultsController sections][section];
return [sectionInfo numberOfObjects];
//return [dayEvents count];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"EventCell"];
[self configureCell:cell atIndexPath:indexPath];
return cell;
}
- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath
{
// Return NO if you do not want the specified item to be editable.
if (_isLocked) {
return NO;
} else {
return YES;
}
}
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
if (editingStyle == UITableViewCellEditingStyleDelete) {
NSManagedObjectContext *context = [self.fetchedResultsController managedObjectContext];
[context deleteObject:[self.fetchedResultsController objectAtIndexPath:indexPath]];
NSError *error = nil;
if (![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();
}
}
}
- (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath
{
// The table view should not be re-orderable.
return NO;
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
Event *event = [self.fetchedResultsController objectAtIndexPath:indexPath];
[event toggleChecked];
[self configureCheckmarkForCell:cell withEvent:event];
[tableView deselectRowAtIndexPath:indexPath animated:YES];
// this updates the detail controller when a row is selected. Not sure we want to do that
if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPad) {
NSManagedObject *object = [[self fetchedResultsController] objectAtIndexPath:indexPath];
self.detailViewController.detailItem = object;
}
}
#pragma mark - Fetched results controller
- (NSFetchedResultsController *)fetchedResultsController
{
if (_fetchedResultsController != nil) {
return _fetchedResultsController;
}
NSLog(@"the fetched results controller is getting the events for %@", self.viewNSDate);
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
// Edit the entity name as appropriate.
NSEntityDescription *entity = [NSEntityDescription entityForName:@"Event" inManagedObjectContext:self.managedObjectContext];
[fetchRequest setEntity:entity];
// Set the batch size to a suitable number.
[fetchRequest setFetchBatchSize:20];
// Edit the sort key as appropriate.
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"eventNSDate" ascending:YES];
NSArray *sortDescriptors = @[sortDescriptor];
[fetchRequest setSortDescriptors:sortDescriptors];
// setup the predicate to return just the wanted date and schedule
NSPredicate *requestPredicate = [NSPredicate predicateWithFormat:[NSString stringWithFormat:@"(eventDate like '%@') AND (schedule.scheduleName like '%@')", [Event returnDateString:self.viewNSDate], self.viewSchedule.scheduleName]];
[fetchRequest setPredicate:requestPredicate];
// Clear out any previous cache
[NSFetchedResultsController deleteCacheWithName:@"Master"];
// 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:@"Master"];
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.
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
abort();
}
// manually set the delegate?
return _fetchedResultsController;
}
- (void)performFetch
{
NSError *error;
if (![self.fetchedResultsController performFetch:&error]) {
//FATAL_CORE_DATA_ERROR(error);
NSLog(@"database error");
return;
}
}
- (void)controllerWillChangeContent:(NSFetchedResultsController *)controller
{
[self.tableView beginUpdates];
}
- (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)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:@[newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeDelete:
[tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeUpdate:
[self configureCell:[tableView cellForRowAtIndexPath:indexPath] atIndexPath:indexPath];
break;
case NSFetchedResultsChangeMove:
[tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationFade];
[tableView insertRowsAtIndexPaths:@[newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller
{
[self.tableView endUpdates];
}