Question

我正在尝试从名为Friends的实体中删除一行。我有一个UITableView，其中dataSource来自实体Friends。我可以从tableview中删除一条记录，但我也想从数据库中删除相关的行。

我可以在这里找到什么？

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    friendsList = [[NSMutableArray alloc] init];

    [self fillTableView];
}

-(void) fillTableView
{
    NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] initWithEntityName:@"Friends"];
    NSError *requestError = nil;
    NSArray *friends = [self.managedObjectContext executeFetchRequest:fetchRequest error:&requestError];

    if([friends count] > 0)
    {
        NSUInteger counter = 1;
        for(Friends *thisFriend in friends)
        {
            [friendsList addObject:thisFriend.fullname];
            counter++;
        }
    }
    else
    {
        NSLog(@"No Friends entity.");
    }
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *simpleTableIdentifier = @"AllFriends";
    UITableViewCell *cell = [tableView
                         dequeueReusableCellWithIdentifier:simpleTableIdentifier];
    if (cell == nil)
    {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault
                                  reuseIdentifier:simpleTableIdentifier];
    }
    cell.textLabel.text = [friendsList objectAtIndex:indexPath.row];
    return cell;
}

-(void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
    if(editingStyle == UITableViewCellEditingStyleDelete)
    {
        [friendsList removeObjectAtIndex:indexPath.row];
        [tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
    }
}

非常感谢任何帮助。谢谢你。

Answer 1

array:- friends contains the records of Friends entity so you have to keep this array.

-(void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
    if(editingStyle == UITableViewCellEditingStyleDelete)
    {
        [friendsList removeObjectAtIndex:indexPath.row];
        [tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];

          // delete from event entity --
            NSManagedObjectContext *context = [self managedObjectContext];
            [context deleteObject:yourObject];         //array friends object at indexPath.row 
            [self.managedObjectContext save:nil];


            [tableView reloadData];
    }
}

从CoreData中删除记录

1 个答案: