Ios 如何正确释放没有控制柄的指定对象

Instruments指出这是内存泄漏，但我不确定如何正确释放它，或者何时应该释放它。 是否有更好的约定用于为仅在循环中需要的新对象指定属性？具体行是

expense.addedDate=[NSDate new]

- (void) addObjects:(NSString *)itemDescription withItemAmount:(NSString *)itemAmount {
// Add a new expense to the persistent store.
NSString *expenseDescription = itemDescription;
NSString *expenseAmount = itemAmount;
if (!expenseDescription.length || !expenseAmount.length) {
    UIAlertView *invalidEntry = [[[UIAlertView alloc] initWithTitle:@"Invalid Entry" 
                                                            message:@"You must include a description and cost." 
                                                           delegate:self 
                                                  cancelButtonTitle:@"OK" 
                                                  otherButtonTitles:nil] autorelease];
    [invalidEntry show];
} else {
    Expense *expense = (Expense *)[NSEntityDescription insertNewObjectForEntityForName:@"Expense"
                                                                inManagedObjectContext:self.managedObjectContext];
    expense.addedDate = [NSDate new];
    expense.itemDescription = expenseDescription;
    expense.cost = [NSNumber numberWithInt:[expenseAmount intValue]];

    NSError *error;
    if (![self.managedObjectContext save:&error]) {
        NSLog(@"Error %@", [error localizedDescription]);
        UIAlertView *errorSave = [[[UIAlertView alloc] initWithTitle:@"Unable to Save!" 
                                                            message:@"Money manager was not able to save this entry." 
                                                           delegate:self 
                                                  cancelButtonTitle:@"OK" 
                                                  otherButtonTitles:nil] autorelease];
        [errorSave show];
    } else {
        NSLog(@"Saved Expense to Database.");
    }
}
}

我想您不想使用
new
选择器，因为它不是自动释放的。如果要查找默认、当前时间戳、自动删除的NSDate对象，应使用：

expense.addedDate = [NSDate date];

记录在案

[NSObject new]

相当于

[[NSObject alloc] init]

如果您声明“expense.addedDate”属性以使用retain（@property（retain）），则不应像指定日期那样指定日期，因为对象的retainCount为2，稍后释放时将导致memleak

相反，使用自动释放对象或在指定后释放对象就足够了

e、 g

或

还是第三条路

NSDate* dt = [[NSDate new] autorelease];

自动释放（so#1或#3）是首选。
NSDate* dt = [NSDate new];
expense.addedDate = dt;
[dt release];

NSDate* dt = [[NSDate new] autorelease];