Iphone 信息：“[CFString retain]：发送到解除分配实例的消息…”是的，您的回答是正确的。数据显示在表视图中，并且我已在接收视图控制器中实现了NSFETCHEEDRESULTSCONTROLLER委托方法。您是否可以尝试\uuuuu bridge而不

---

信息：“[CFString retain]：发送到解除分配实例的消息…”是的，您的回答是正确的。数据显示在表视图中，并且我已在接收视图控制器中实现了NSFETCHEEDRESULTSCONTROLLER委托方法。您是否可以尝试

\uuuuu bridge

而不是

\uuuu bridge\uu transfer

？看起来您的CFString对象发布得太快了。或者让它保持原样，不要发布

uuiString

，因为根据我对文档的理解，ARC正在为您这样做。谢谢！这就是问题所在。花时间回顾了“桥”和“桥”之间的区别。

- (void)didCancelNewLoan:(Loan *)loan {
    // save the context
    NSManagedObjectContext *context = [self.fetchedResultsController managedObjectContext];

    [context deleteObject:loan];  // *** EXC_BAD_ACCESS here ***

// This method is called from a the following method in a second class:

- (IBAction)cancel:(id)sender {
    [delegate didCancelNewLoan:self.loan];
}

// The loan ivar is created by the original class
// in the below prepare for Segue method:

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {

    if ([segue.identifier isEqualToString:@"NewLoan"]) {
        UINavigationController *navController = (UINavigationController *)[segue destinationViewController];
        LoanViewController *loanView = (LoanViewController *)[[navController viewControllers] lastObject];
        loanView.managedObjectContext = self.managedObjectContext;
        loanView.delegate = self;

        loanView.loan = [self createNewLoan];
        loanView.newLoan = YES;
    }


// Finally, the loan is created in the above
// method's [self createNewLoan] command:

- (NSManagedObject *)createNewLoan {
    //create a new instance of the entity managed by the fetched results controller
    NSManagedObjectContext *context = [self.fetchedResultsController managedObjectContext];
    NSEntityDescription *entity = [[self.fetchedResultsController fetchRequest] entity];
    NSManagedObject *newManagedObject = [NSEntityDescription insertNewObjectForEntityForName:[entity name] inManagedObjectContext:context];
    [newManagedObject setValue:[NSDate date] forKey:@"timeStamp"];

    CFUUIDRef uuid = CFUUIDCreate(NULL);
    CFStringRef uuidstring = CFUUIDCreateString(NULL, uuid);
    //NSString *identifierValue = (__bridge_transfer NSString *)uuidstring;
    [newManagedObject setValue:(__bridge_transfer NSString *)uuidstring forKey:@"identifier"];
    CFRelease(uuid);
    CFRelease(uuidstring);

    NSError *error;
    [self.fetchedResultsController performFetch:&error];
    NSLog(@"%i items in database", [[self.fetchedResultsController fetchedObjects] count]);

    return newManagedObject;
}

assert( [ NSThread isMainThread ] ) ;

- (IBAction)cancel:(id)sender 
{
    NSError *error;
    NSManagedObjectContext *context = [self.loan managedObjectContext];
    [context deleteObject:self.loan];
    if (![context save:&error])
         NSLog (@"Error saving context: %@", error);
}

- (void)dealloc {
    fetchedResultsController.delegate = nil;
}