Person:
-(BOOL)hasPet;
-(BOOL)hasDog;

基本上,我希望我的表只显示那些有宠物的Person对象.这很简单,我可以使用谓词.现在,对于那些hasPet == YES的人,我想把它们放在表中的2个部分中,第一部分是hasDog == YES,第二部分是hasDog == NO.这是我有点模糊的地方.这是我配置结果控制器的地方,希望有人可以帮助引导我朝着正确的方向前进.

- (NSFetchedResultsController *)fetchedResultsController {
if (nil != fetchedResultsController) {
    return fetchedResultsController;
}

NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:@"Homework" inManagedObjectContext:managedObjectContext];
[fetchRequest setEntity:entity];

NSPredicate *predicate = [NSPredicate predicateWithFormat:@"hasPet == %@",[NSNumber numberWithBool:YES]];
[fetchRequest setPredicate:predicate];

NSSortDescriptor *dogDescriptor = [[NSSortDescriptor alloc] initWithKey:@"hasDog" ascending:YES];
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"name" ascending:YES];
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:dogDescriptor,sortDescriptor,nil];

[fetchRequest setSortDescriptors:sortDescriptors];

NSFetchedResultsController *aController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:managedObjectContext sectionNameKeyPath:nil cacheName:nil];
aController.delegate = self;
self.fetchedResultsController = aController;

    // Release things

return fetchedResultsController;
}

是一个排序描述符,我需要关注我的注意力吗？

解决方法

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