我正在使用核心数据构建应用。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“Clocks”并添加了一堆行。
我的RootViewController呈现了一个具有UINavigationController的MVC。当我将数据保存到我的数据库时，UINavigationController类使用[[UIApplication sharedApplication]delegate]保存数据以访问我实际执行保存操作的appDelegate。
编辑数据的方式相同，但不是在我的app委托中调用insert函数，而是调用更新函数。
现在，这一切都很好......实际上完全正确。但是......几次打开编辑并保存在视图中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（电影）的一个例子：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
修改
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，
保罗佩伦
答案 0 :(得分：7)
托管对象失效问题： 你会看到一个看起来异常 类似于这个例子：
[_assignObject：toPersistentStore：]： 具有ID：####的NSManagedObject具有 已失效。原因：要么你 已经删除了商店的故障 你正试图开火，或者 托管对象的上下文已发送 重置消息。
补救措施：你应该放弃这个 宾语。如果再次添加商店， 你可以尝试再次获取对象
因此，基本上，您有一个对已与其商店或上下文断开连接的托管对象的引用。
我没有看到明显的地方发生这种情况，但是您要在tableView:cellForRowAtIndexPath:中向托管对象发送保留消息：
NSManagedObject *managedObject = [[self.fetchedResultsController objectAtIndexPath:indexPath] retain];
......即使你随后发布它也很危险。永远不要保留托管对象，而是依赖上下文来保留它。否则，上下文可能释放托管对象并将其标记为无效，而另一个对象使其保持活动状态。
我建议您浏览所有代码并找到您向托管对象发送保留的所有位置，并删除不必要的保留/释放代码。这可能会解决问题。
如果不是，您需要检查您的持久存储是否仍然正确分配给持久性存储协调器。
答案 1 :(得分：1)
我遇到过这个问题，我已经通过评论RESET为此问题从苹果文档中解释了此问题的管理对象上下文：
您可以使用NSManagedObjectContext的reset方法删除与上下文关联的所有托管对象，并“重新开始”，就像您刚刚创建它一样。请注意，与该上下文关联的任何托管对象都将无效，因此您需要放弃对您仍然感兴趣的上下文关联的任何对象的引用和重新获取。