Question

我正在尝试更新存储在核心数据实体中的布尔值，无论我尝试什么，它似乎都不会更新。这是我正在使用的方法：

+ (void) updateTimeFormatPreferenceForUserWithNumber:(NSString *)number withBool:(BOOL)preference WithContext:(NSManagedObjectContext *)context {

    NSFetchRequest * fetchRequest = [[NSFetchRequest alloc] init];
    NSPredicate *predicate = [NSPredicate predicateWithFormat:@"mobileNumber == %@", number];

    [fetchRequest setPredicate:predicate];
    [fetchRequest setEntity:[NSEntityDescription entityForName:@"User" inManagedObjectContext:context]];
    [fetchRequest setIncludesPropertyValues:YES];

    NSError *error = nil;
    NSArray *result = [context executeFetchRequest:fetchRequest error:&error];

    if ([result count] > 0){

        User *user = [result objectAtIndex:0];
        [user setTwentyFourHourTime:[NSNumber numberWithBool:preference]];

        if (![context save:&error]) {
            NSLog(@"Whoops, couldn't save: %@", [error localizedDescription]);
        } else {

            BOOL twentyFourHour = [[CoreDataUtils getUserWithNumber:number WithContext:context] twentyFourHourTime];

            NSLog(@"Saved Preference %s", preference ? "True" : "False");
            NSLog(@"From user object: %@", [user twentyFourHourTime]);
            NSLog(@"Twenty Four Hour Time is: %s", twentyFourHour ? "true" : "false");
        }
    }
}

使用preference属性调用此方法，因为true和false都具有以下输出：

Saved Preference False
From user object: 0
Twenty Four Hour Time is: true
Saved Preference True
From user object: 1
Twenty Four Hour Time is: true
Saved Preference False
From user object: 0
Twenty Four Hour Time is: true
Saved Preference True
From user object: 1
Twenty Four Hour Time is: true

二十几岁的布尔永远不会改变，它让我疯狂，为什么不更新？

getUserWithNumber方法是：

+ (User *) getUserWithNumber:(NSString *)number WithContext:(NSManagedObjectContext *)context {

    NSFetchRequest * fetchRequest = [[NSFetchRequest alloc] init];
    NSPredicate *predicate = [NSPredicate predicateWithFormat:@"mobileNumber == %@", number];

    [fetchRequest setPredicate:predicate];
    [fetchRequest setEntity:[NSEntityDescription entityForName:@"User" inManagedObjectContext:context]];
    [fetchRequest setIncludesPropertyValues:YES];

    NSError *error = nil;
    NSArray *result = [context executeFetchRequest:fetchRequest error:&error];

    if ([result count] > 0){
        return [result objectAtIndex:0];
    } else {
        return nil;
    }
}

三江源

Answer 1

这一行

BOOL twentyFourHour = [[CoreDataUtils getUserWithNumber:number WithContext:context] twentyFourHourTime];

不正确，因为您正在将NSNumber个实例保存到BOOL变量中，因此您确实在测试是否已设置该数字而不是bool的值。将其更改为

BOOL twentyFourHour = [[[CoreDataUtils getUserWithNumber:number WithContext:context] twentyFourHourTime] boolValue];

核心数据实体未更新

1 个答案: