NSInvalidArgumentException',原因:'谓词的未知谓词类型:BLOCKPREDICATE(0x70ad750)'错误

Question

我有一个核心数据库,我正在尝试使用块谓词创建一个获取请求,但是我得到一个未知谓词错误:

注意: employeeToHouse是我在子类化NSManagedObject时为我创建的House类型的属性

NSFetchRequest *request = [NSFetchRequest fetchRequestWithEntityName:@"Place"];
request.predicate       = [NSPredicate predicateWithBlock:^BOOL(id evaluatedObject, NSDictionary *bindings) {
    Place *sortPlace            = (Place *)evaluatedObject;
    CLLocation *placeLocation   = [[CLLocation alloc] initWithLatitude:sortPlace.latitude.doubleValue 
                                                             longitude:sortPlace.longitude.doubleValue];
    CLLocationDistance distance = [placeLocation distanceFromLocation:self.userLocation];
    sortPlace.distanceToUser    = [NSNumber numberWithDouble:distance];
    if(distance<3000)
    {
        return YES;
    }
    return NO;
}];
request.sortDescriptors = [NSArray arrayWithObject:[NSSortDescriptor sortDescriptorWithKey:@ "distanceToUser" 
                                                                                 ascending:YES 
                                                                                  selector:@selector(localizedCaseInsensitiveCompare:)]];

[self.loadingView removeSpinner];
[self setupFetchedResultsControllerWithFetchRequest:request];

然后我得到这个错误:

NSInvalidArgumentException',原因:'谓词的未知谓词类型:BLOCKPREDICATE(0x70ad750)'

难道我做错了什么？

Answer 1

AFAIK您不能在CoreData中使用块谓词.

请参阅此处的最高投票答案:NSFetchRequest和predicateWithBlock

原因是CoreData无法将块中包含的C代码转换为SQL查询.