我正在使用核心数据构建应用程序。由 appDelegate 加载的我的 RootViewController 主要来自模板。但是我已将实体名称更改为“时钟”并添加了一堆行。
我的 RootViewController 提供了一个具有 UINavigationController 的 MVC。当我将数据保存到我的数据库时，UINavigationController 类保存了[[UIApplication sharedApplication]delegate]用于访问我的 appDelegate 的数据，该 appDelegate 实际执行了保存操作。编辑数据的方式相同，但不是在我的应用程序委托中调用插入函数，而是调用更新函数。
现在，这一切都很好……实际上非常完美。但是......几次打开编辑并保存在视图中后，我的应用程序崩溃了。它在模拟器和我的 iPhone 4 上都这样做。这是我的意思的一个例子（电影）：http ://dl.dropbox.com/u/3077127/has_been_invalidated.mov
这是我的 RootViewController.m 的代码：
#import "RootViewController.h"
#import "RootViewControllerClockCell.h"
#import "RootViewControllerClockCellFooter.h"
#import "configuration.h"
#import "AddClockViewController.h"
#import "clockAppDelegate.h"
#import "AddClockNavigationController.h"
@interface RootViewController ()
- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath;
@end
@implementation RootViewController
@synthesize fetchedResultsController=fetchedResultsController_, managedObjectContext=managedObjectContext_;
#pragma mark -
#pragma mark View lifecycle
- (void)viewDidLoad {
[super viewDidLoad];
[self setTitle:NSLocalizedString(@"Alarms", @"AddClockNavigationController")];
// Set up the edit and add buttons.
self.navigationItem.leftBarButtonItem = self.editButtonItem;
UIBarButtonItem *addButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(showAddAlarmView)];
self.navigationItem.rightBarButtonItem = addButton;
[addButton release];
[self.tableView setSeparatorStyle:UITableViewCellSeparatorStyleNone];
[self.tableView setBackgroundColor:[UIColor clearColor]];
[self.tableView setBackgroundView:[[[UIImageView alloc] initWithImage:[UIImage imageNamed:@"clockTableBackground"]] autorelease]];
[self.tableView setAllowsSelectionDuringEditing:YES];
if (managedObjectContext_ == nil)
{
managedObjectContext_ = [(ClockAppDelegate *)[[UIApplication sharedApplication] delegate] managedObjectContext];
NSLog(@"After managedObjectContext: %@", managedObjectContext_);
}
locationManager = [[CLLocationManager alloc] init];
locationManager.delegate=self;
locationManager.desiredAccuracy=kCLLocationAccuracyBest;
[locationManager startUpdatingLocation];
}
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation {
location = newLocation.coordinate;
[locationManager stopUpdatingLocation];
[self.tableView reloadData];
}
- (void)viewWillDisappear:(BOOL)animated
{
[locationManager stopUpdatingLocation];
[super viewWillDisappear:animated];
}
// Implement viewWillAppear: to do additional setup before the view is presented.
- (void)viewWillAppear:(BOOL)animated {
[locationManager startUpdatingLocation];
[super viewWillAppear:animated];
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
if ([Configuration isIpad])
{
return YES;
}
else {
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
}
- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath {
// @TODO
// Remove unused function
}
- (void)showAddAlarmView
{
AddClockNavigationController *viewController = [[AddClockNavigationController alloc] initWithNibName:@"AddClockNavigationController" bundle:nil];
[[self navigationController] presentModalViewController:viewController animated:YES];
[viewController release];
}
#pragma mark -
#pragma mark Add a new object
- (void)setEditing:(BOOL)editing animated:(BOOL)animated
{
[super setEditing:(BOOL)editing animated:(BOOL)animated];
self.navigationItem.rightBarButtonItem.enabled = !editing;
}
#pragma mark -
#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];
int retValue = [sectionInfo numberOfObjects];
retValue++;
return retValue;
}
// Customize the appearance of table view cells.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
id <NSFetchedResultsSectionInfo> sectionInfo = [[self.fetchedResultsController sections] objectAtIndex:indexPath.section];
if (indexPath.row < [sectionInfo numberOfObjects])
{
static NSString *CellIdentifier = @"RootViewControllerClockCell";
RootViewControllerClockCell *cell = (RootViewControllerClockCell*)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil){
NSArray *topLevelObjects = [[NSBundle mainBundle] loadNibNamed:@"RootViewControllerClockCell" owner:nil options:nil];
for(id currentObject in topLevelObjects)
{
if([currentObject isKindOfClass:[RootViewControllerClockCell class]])
{
cell = (RootViewControllerClockCell *)currentObject;
break;
}
}
}
// Configure the cell.
NSManagedObject *managedObject = [[self.fetchedResultsController objectAtIndexPath:indexPath] retain];
[[cell titleText] setText:[[managedObject valueForKey:@"title"] description]];
UISwitch *mySwitch = [[[UISwitch alloc] initWithFrame:CGRectZero] autorelease];
[cell addSubview:mySwitch];
cell.accessoryView = mySwitch;
[cell setSelectionStyle:UITableViewCellSelectionStyleNone];
[mySwitch setTag:indexPath.row];
BOOL isOn = [(NSNumber*)[managedObject valueForKey:@"active"] boolValue];
[(UISwitch *)cell.accessoryView setOn:isOn];
[(UISwitch *)cell.accessoryView addTarget:self action:@selector(setClockEnabled:) forControlEvents:UIControlEventValueChanged];
[cell setEditingAccessoryType:UITableViewCellAccessoryDisclosureIndicator];
[currentLocation release];
[cellLocation release];
[managedObject release];
return cell;
}
else {
static NSString *CellIdentifier = @"RootViewControllerClockCellFooter";
RootViewControllerClockCellFooter *cell = (RootViewControllerClockCellFooter*)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil){
NSArray *topLevelObjects = [[NSBundle mainBundle] loadNibNamed:@"RootViewControllerClockCellFooter" owner:nil options:nil];
for(id currentObject in topLevelObjects)
{
if([currentObject isKindOfClass:[RootViewControllerClockCellFooter class]])
{
cell = (RootViewControllerClockCellFooter *)currentObject;
break;
}
}
}
return cell;
}
}
- (NSString*)distanceToString:(double)distance
{
NSString *returnString = @"";
if (distance < 1000)
{
returnString = [NSString stringWithFormat:@"%gm", round(distance)];
}
else {
returnString = [NSString stringWithFormat:@"%gkm", round(distance/1000)];
}
return returnString;
}
- (void)setClockEnabled:(UISwitch*)sender
{
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:sender.tag inSection:0];
NSManagedObject *managedObject = [self.fetchedResultsController objectAtIndexPath:indexPath];
[managedObject setValue:[NSNumber numberWithBool:sender.on] forKey:@"active"];
NSError *error = nil;
if (![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();
}
}
// Override to support conditional editing of the table view.
- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath
{
id <NSFetchedResultsSectionInfo> sectionInfo = [[self.fetchedResultsController sections] objectAtIndex:indexPath.section];
if ((indexPath.row > [sectionInfo numberOfObjects]-1) || [self.tableView numberOfRowsInSection:indexPath.section] == 1)
return NO;
else
return YES;
}
// Override to support editing the table view.
- (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]];
// Save the context.
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. 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();
}
if ([self.tableView numberOfRowsInSection:0] == 1)
{
[self.tableView reloadData];
}
}
}
- (void)updateAlarm:(NSManagedObject*)originalAlarm withAlarm:(NSManagedObject*)newAlarm
{
NSLog(@"Update!");
NSManagedObjectContext *context = [self.fetchedResultsController managedObjectContext];
[context deleteObject:originalAlarm];
[context insertObject:newAlarm];
// Save the context.
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. 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();
}
}
- (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath {
// The table view should not be re-orderable.
return NO;
}
#pragma mark -
#pragma mark Table view delegate
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
NSLog(@"Did select row");
if ([self.tableView isEditing])
{
// Show editing mode
NSManagedObject *managedObject = [self.fetchedResultsController objectAtIndexPath:indexPath];
AddClockNavigationController *viewController = [[AddClockNavigationController alloc] initWithNibName:@"AddClockNavigationController" bundle:nil editManagedObject:managedObject];
[[self navigationController] presentModalViewController:viewController animated:YES];
[viewController release];
}
}
- (void)cancelAddAlarmView
{
[self.modalViewController dismissModalViewControllerAnimated:YES];
}
#pragma mark -
#pragma mark Fetched results controller
- (NSFetchedResultsController *)fetchedResultsController {
if (fetchedResultsController_ != nil) {
return fetchedResultsController_;
}
/*
Set up the fetched results controller.
*/
// Create the fetch request for the entity.
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
// Edit the entity name as appropriate.
NSEntityDescription *entity = [NSEntityDescription entityForName:@"Clocks" 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:@"addDate" 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:@"Root"];
aFetchedResultsController.delegate = self;
self.fetchedResultsController = aFetchedResultsController;
[aFetchedResultsController release];
[fetchRequest release];
[sortDescriptor release];
[sortDescriptors release];
NSError *error = nil;
if (![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_;
}
#pragma mark -
#pragma mark Fetched results controller delegate
- (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:[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.tableView endUpdates];
}
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
id <NSFetchedResultsSectionInfo> sectionInfo = [[self.fetchedResultsController sections] objectAtIndex:indexPath.section];
if (indexPath.row < [sectionInfo numberOfObjects])
{
return 92;
}
else {
return 40;
}
}
/*
// Implementing the above methods to update the table view in response to individual changes may have performance implications if a large number of changes are made simultaneously. If this proves to be an issue, you can instead just implement controllerDidChangeContent: which notifies the delegate that all section and object changes have been processed.
- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller {
// In the simplest, most efficient, case, reload the table view.
[self.tableView reloadData];
}
*/
#pragma mark -
#pragma mark Memory management
- (void)didReceiveMemoryWarning {
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Relinquish ownership any cached data, images, etc that aren't in use.
}
- (void)viewDidUnload {
// Relinquish ownership of anything that can be recreated in viewDidLoad or on demand.
// For example: self.myOutlet = nil;
}
- (void)dealloc {
[fetchedResultsController_ release];
[managedObjectContext_ release];
[locationManager stopUpdatingLocation];
[locationManager release];
[super dealloc];
}
@end
编辑
这是保存按钮的代码， AddClockNavigationController.m：
- (IBAction)saveAlarm
{
[self saveTheAlarm];
}
- (void)saveTheAlarm
{
AddClockViewController *viewController = [navigationController.viewControllers objectAtIndex:0];
UITableView *alarmTable = viewController.theTable;
NSIndexPath *textFieldIndexPath = [NSIndexPath indexPathForRow:0 inSection:0];
UITextField *textField = (UITextField*)[[alarmTable cellForRowAtIndexPath:textFieldIndexPath] accessoryView];
ClockAppDelegate *appDelegate = (ClockAppDelegate*)[[UIApplication sharedApplication] delegate];
RootViewController *parentView = [[RootViewController alloc] init];
[appDelegate addNewAlarmWithTitle:textField.text sound:@"" recurring:[viewController hasRecurring] recurringDays:viewController.recurringDictionary];
[parentView.tableView reloadData];
[self.parentViewController dismissModalViewControllerAnimated:YES];
[parentView release];
}
ClockAppDelegate.m
- (void)addNewAlarmWithTitle:(NSString*)alarmTitle sound:(NSString*)sound recurring:(BOOL)isRecurring recurringDays:(NSDictionary*)days
{
NSManagedObjectContext *context = managedObjectContext_;
NSManagedObject *newManagedObject = [NSEntityDescription insertNewObjectForEntityForName:@"Clocks" inManagedObjectContext:context];
[newManagedObject setValue:alarmTitle forKey:@"title"];
[newManagedObject setValue:sound forKey:@"alarm"];
[newManagedObject setValue:[NSNumber numberWithBool:TRUE] forKey:@"active"];
[newManagedObject setValue:[[NSDate alloc] init] forKey:@"addDate"];
[newManagedObject setPrimitiveValue:[NSNumber numberWithBool:isRecurring] forKey:@"recurring"];
NSArray *myKeys = [days allKeys];
NSArray *sortedKeys = [myKeys sortedArrayUsingSelector:@selector(caseInsensitiveCompare:)];
for (id key in sortedKeys) {
if ([(NSString*)[days objectForKey:key] isEqualToString:@"1"])
{
if ([key isEqualToString:@"0"])
{
[newManagedObject setPrimitiveValue:[NSNumber numberWithBool:TRUE] forKey:@"mon"];
}
else if ([key isEqualToString:@"1"])
{
[newManagedObject setPrimitiveValue:[NSNumber numberWithBool:TRUE] forKey:@"tue"];
}
else if ([key isEqualToString:@"2"])
{
[newManagedObject setPrimitiveValue:[NSNumber numberWithBool:TRUE] forKey:@"wed"];
}
else if ([key isEqualToString:@"3"])
{
[newManagedObject setPrimitiveValue:[NSNumber numberWithBool:TRUE] forKey:@"thu"];
}
else if ([key isEqualToString:@"4"])
{
[newManagedObject setPrimitiveValue:[NSNumber numberWithBool:TRUE] forKey:@"fri"];
}
else if ([key isEqualToString:@"5"])
{
[newManagedObject setPrimitiveValue:[NSNumber numberWithBool:TRUE] forKey:@"sat"];
}
else if ([key isEqualToString:@"6"])
{
[newManagedObject setPrimitiveValue:[NSNumber numberWithBool:TRUE] forKey:@"sun"];
}
}
}
// Save the context.
NSError *error = nil;
if (![context save:&error]) {
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
abort();
}
}
我做错了什么？
最好的问候，
保罗·皮伦