ios - 为 NSArray 订购返回的 CoreData 实体

Question

我正在尝试通过“出发时间”属性的值来排列返回的核心数据实体，目前我有这段代码，但顺序没有改变，它们以相同的顺序保存到数组中，而不管 NSSortDescriptor

NSFetchRequest *request = [[NSFetchRequest alloc] initWithEntityName:@"Device"];

NSPredicate *predicate = [NSPredicate predicateWithFormat:@"thetrip=%@",searchid];

[request setEntity:[NSEntityDescription entityForName:@"Device" inManagedObjectContext:managedObjectContext]];

[request setPredicate:predicate];
self.device = [[managedObjectContext executeFetchRequest:request error:nil] mutableCopy];
[NSSortDescriptor sortDescriptorWithKey:@"departtime" ascending:YES];
NSLog(@"the predicate is= %@", predicate);

NSError *error = nil;

NSArray *results = [managedObjectContext executeFetchRequest:request error:&error];

NSArray *areuslter=[self.device valueForKey:@"arriveairport"];
NSArray *areusltses=[self.device valueForKey:@"thetrip"];

Answer 1

您实际上并没有对那里的 SortDescriptor 做任何事情。事实上，您完全忽略了它。

试试这个...

NSSortDescriptor *timeSD = [NSSortDescriptor sortDescriptorWithKey:@"departtime" ascending:YES];
[request setSortDescriptors:@[timeSD]];

这会将排序描述符添加到请求中。