java - "likeCount"增量器的 boolean 逻辑

Question

我创建了这个 incrementLike 方法来递增我的数据库中的一个整数。不幸的是，我无法弄清楚如何阻止用户在每次单击“喜欢”图像时不断增加该值。

我想 likeAlready = true 语句无法访问，因为它似乎总是 false。我的逻辑/实现有什么问题？

private void incrementLike(int position) {
        ParseQuery<ParseObject> query = new ParseQuery<>("Comment");
        query.whereEqualTo(ParseConstants.KEY_OBJECT_ID, getItem(position).getObjectId());
        query.findInBackground((comment, e) -> {
            if (e == null) {
                // Iterate over all messages and delete them
                for (ParseObject commentObject : comment)
                {
                    boolean likedAlready = false;
                    if (likedAlready == false) {
                        commentObject.increment("likeCount");
                        commentObject.saveInBackground();
                        Toast.makeText(getContext(), "Post liked", Toast.LENGTH_SHORT).show();
                        likedAlready = true;
                    } else {
                        Toast.makeText(getContext(), "You already liked this post", Toast.LENGTH_SHORT).show();
                    }

                }
            } else {
                Log.e("Error", e.getMessage());
            }
        });
    }

更新:

我创建了一个名为“Like”的新类表，其中包含两个指针列，即 senderId，即用户的 objectId 和 commentObjectId，即相关评论的 objectId。

当按下“赞”图像时，我在“赞”表中创建一个新对象，其中包含 senderId 和 commentObjectId。最后一步是确定是否已经为该特定 Comment 对象发送了 senderId。这是我目前所拥有的:

private void incrementLike(int position) {

        ParseQuery<ParseObject> query = new ParseQuery<>(ParseConstants.CLASS_COMMENT);
        query.whereEqualTo(ParseConstants.KEY_OBJECT_ID, getItem(position).getObjectId());
        query.findInBackground((comment, e) -> {
            if (e == null) {
                // Iterate over all messages
                for (ParseObject commentObject : comment)
                {

                    ParseObject newLike = new ParseObject(ParseConstants.CLASS_LIKE);
                    newLike.put(ParseConstants.KEY_SENDER_ID, ParseUser.getCurrentUser());
                    newLike.put(ParseConstants.KEY_COMMENT_OBJECT_ID, commentObject);
                    newLike.saveInBackground();
                    Toast.makeText(getContext(), "Yeet liked", Toast.LENGTH_SHORT).show();

                    ParseQuery<ParseObject> query2 = new ParseQuery<>(ParseConstants.CLASS_LIKE);
                    query2.whereEqualTo(ParseConstants.KEY_COMMENT_OBJECT_ID, commentObject.getObjectId());
                    query2.findInBackground((comment2, e2) -> {
                        if (e2 == null) {

                            // I now have a list of Like objects with the commentObjectId associated with this Comment
                            // Only increment if the User objectId of the current ParseUser does not exist in this list
                            commentObject.increment("likeCount");
                            commentObject.saveInBackground();
                            /*this.adapter.addAll(mYeets);*/
                            notifyDataSetChanged();


                        } else {
                            Log.e("Error", e2.getMessage());
                        }
                    });

                }
            } else {
                Log.e("Error", e.getMessage());
            }
        });
    }

我在思考最后一步时遇到了麻烦。有什么建议吗？

Answer 1

Unfortunately I can't figure out how to stop the user from continually incrementing that value every time they click the "like" image.

您当前代码中的简单 boolean 逻辑实际上是不可行的，因为除了递增数据库存储计数器之外，您还必须存储递增它的信息(即用户 ID)(也在数据库中)。您可以提前检查并仅在该用户尚未这样做时才显示“喜欢”按钮。