NSSortDescriptor代码中存在iOS内存泄漏

Question

我在下面的class辅助函数中遇到内存泄漏（请参阅下面的>>）。

    + (NSArray *)findAllRoomsInContext:(NSManagedObjectContext *)context;
{
    NSEntityDescription *entity = [self entityDescriptionInContext:context];
    NSFetchRequest *request = [[[NSFetchRequest alloc] init] autorelease];
    [request setEntity:entity];
    >> NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"name" ascending:YES selector:@selector(localizedCaseInsensitiveCompare:)]; 
    >> NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil]; 
    [request setSortDescriptors:sortDescriptors];
    NSError *error = nil;
    NSArray *results = [context executeFetchRequest:request error:&error];
    if (error != nil)
    {
        //handle errors
    }
    sortDescriptors = nil;
    return results;
}

Answer 1

分配sortDescriptor和sortDescriptors，但在结束时不释放它们

NSSortDescriptor *sortDescriptor = [[[NSSortDescriptor alloc] initWithKey:@"name" ascending:YES selector:@selector(localizedCaseInsensitiveCompare:)] autorelease]; 
NSArray *sortDescriptors = [NSArray arrayWithObjects:sortDescriptor, nil];