Question

我对ios编程很新，并且要解析，所以如果我没有明确解释某些内容，我会非常乐意尽力扩展它。

在解析中我有三个表User Activity和post我现在的代码很适合“跟随”关系，但不适合“喜欢”关系，我想要从Post表获取对象id，并从User表中获取喜欢帖子的用户的对象ID，并将它们插入Activity表。任何帮助将不胜感激，谢谢你提前。

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
 {
if (indexPath.section == self.objects.count && self.paginationEnabled) {
    [self loadNextPage];
    }
}

 - (PFQuery *)queryForTable
{
 PFQuery *query = [PFQuery queryWithClassName:self.parseClassName];
 [query includeKey:@"User"];
 query.cachePolicy = kPFCachePolicyCacheThenNetwork;
 [query whereKey:@"filter" hasPrefix:@"90"];
 [query orderByDescending:@"createdAt"];


    return query;

}




 - (void)likeButton:(LikeButton *)button didTapWithSectionIndex:(NSInteger)index {
PFObject *post = [self.objects objectAtIndex:index];
[post fetchIfNeeded];
PFUser *user = post[@"User"];

if (!button.selected) {
    [self likePost:user];
}
else {
    [self unlikePost:user];
}
    [self.tableView reloadData];
}





 - (void)likePost:(PFUser *)user {
if (![user.objectId isEqualToString:[PFUser currentUser].objectId]) {
    [self.likeArray addObject:user.objectId];
    PFObject *likeActivity = [PFObject objectWithClassName:@"Activity"];
    likeActivity[@"fromUser"] = [PFUser currentUser];
    likeActivity[@"toPost"] = user;
    likeActivity[@"type"] = @"Like";
    [likeActivity saveEventually];
   }
}
- (void)unlikePost:(PFUser *)user {
[self.likeArray removeObject:user.objectId];
PFQuery *query = [PFQuery queryWithClassName:@"Activity"];
[query whereKey:@"fromUser" equalTo:[PFUser currentUser]];
[query whereKey:@"toPost" equalTo:user];
[query whereKey:@"type" equalTo:@"like"];
[query findObjectsInBackgroundWithBlock:^(NSArray *likeActivities, NSError *error) {
    if (!error) {
        for (PFObject *likeActivity in likeActivities) {
            [likeActivity deleteEventually];
        }
    }

    }];
}

Answer 1

好的，首先我会提到你应该非常小心区分大小写。 Parse中的字符串匹配区分大小写，因此如果您使用type:@"Like"创建它，然后尝试使用whereKey:@"type" equalTo:@"like"找到它，那么您将无法获得匹配！

现在，对于您的代码，您想要将当前用户链接到所选帖子吗？

如果是这样，那么你应该做些什么的样本：

- (void)likeButton:(LikeButton *)button didTapWithSectionIndex:(NSInteger)index {
    PFObject *post = [self.objects objectAtIndex:index];

    if (!button.selected) {
        [self likePost:post];
    }
    else {
        [self unlikePost:post];
    }

- (void)likePost:(PFObject *)post {
    [self.likeArray addObject:user.objectId];
    PFObject *likeActivity = [PFObject objectWithClassName:@"Activity"];
    likeActivity[@"fromUser"] = [PFUser currentUser];
    likeActivity[@"toPost"] = post;
    likeActivity[@"type"] = @"like";
    [likeActivity saveEventually];
}

您的代码似乎是从您的＆＃34;关注＆＃34;中复制粘贴的。逻辑，但没有更新，以反映你现在正在做＆＃34;喜欢＆＃34;的事实，所以我已经为你解决了这个问题。您还需要对unlikePost:方法进行类似的更改。

使用指针＆＃34;喜欢＆＃34;解析中的关系

1 个答案: