iphone - 如何在核心数据中对提取进行排序

Question

我正在获取数据以在 UITableView 中显示它，我进行了获取，但我想按创建日期或任何排序方法对它们进行排序。

方法如下:

-(NSArray *) lesStations {

NSManagedObjectContext *moc = [[AppDelegate sharedAppDelegate]managedObjectContext];

NSFetchRequest *fetch = [[NSFetchRequest alloc] init];
NSEntityDescription *entity =  [NSEntityDescription entityForName:@"Station" inManagedObjectContext:moc];

[fetch setEntity:entity];
NSError *error;

NSArray *result = [moc executeFetchRequest:fetch error:&error];

if (!result) {
    return nil;
}

return result;

}

Answer 1

这应该可行

-(NSArray *) lesStations {

    NSManagedObjectContext *moc = [[AppDelegate sharedAppDelegate]managedObjectContext];

    NSFetchRequest *fetch = [[NSFetchRequest alloc] init];
    NSEntityDescription *entity =  [NSEntityDescription entityForName:@"Station" inManagedObjectContext:moc];

    [fetch setEntity:entity];
    NSError *error;

    NSArray *result = [moc executeFetchRequest:fetch error:&error];

    if (!result) {
        return nil;
    }

    NSSortDescriptor *sort = [[NSSortDescriptor alloc] initWithKey:"creationDate" ascending:YES];



    NSArray *sortedResults = [result sortedArrayUsingDescriptors:[NSArray arrayWithObject:sort]];

    [sort release];

    return sortedResults;

}