objective-c - NSDictionary不会填满

我有以下代码。

-(NSDictionary *)getPlayers
{

    NSManagedObjectContext *context = self.genkDatabase.managedObjectContext;

    NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
    NSEntityDescription *entity = [NSEntityDescription entityForName:@"Team"
                                              inManagedObjectContext:context];
    fetchRequest.predicate = [NSPredicate predicateWithFormat:@"position ==[c] %@", @"Doelman"];
    [fetchRequest setEntity:entity];

    NSError *error;
    NSArray *fetchedObjects = [context executeFetchRequest:fetchRequest error:&error];
    if (fetchedObjects == nil) {
        // Handle the error.
    }else

        for (Team *info in fetchedObjects) {

            [_photos setObject:info.image  forKey:@"player_imgUrl"];
            [_photos setObject:info.name forKey:@"player_name"];


        }
    NSLog(@"%@",_photos);
    return _photos;

但是出于某种原因，我的NSLog总是返回（空）。但是当我这样做时

[_photos setObject:info.image  forKey:@"player_imgUrl"];
            [_photos setObject:info.name forKey:@"player_name"];

            NSLog(@"name: %@",info.name );
            NSLog(@"url: %@",info.image );

它返回正确的数据。

有人可以帮忙吗？

亲切的问候。

最佳答案

确保使用以下代码行将_photos字典实例化：

_photos = [[NSMutableDictionary alloc] init];

仅将其定义为实例变量或属性是不够的。

关于objective-c - NSDictionary不会填满，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/12725270/