如何使用ParseQueryAdapter从另一个类获取数据（Android + Parse）

Question

I'm trying to display the username and a photo in aa list view using the ParseQueryAdapter . I have the classes: User and Post .

I set it up here:

String[] postsObjectIds = some_string_array

ParseQueryAdapter<Post> adapter = new ParseQueryAdapter<Post>(getActivity(), new ParseQueryAdapter.QueryFactory<Post>() {
        public ParseQuery<Post> create() {
            ParseQuery<Post> query = Post.getQuery();
            query.include("User");
            query.whereContainedIn("objectId", Arrays.asList(postsObjectIds));
            return query;
        }
});

adapter.setTextKey("username");
adapter.setImageKey("photo");
adapter.setPlaceholder(getResources().getDrawable(R.drawable.some_drawable));

ListView listView = (ListView) rootView.findViewById(R.id.post_list_view);
listView.setAdapter(adapter);

The Post class has a column called photo and the User class has a column called username . The list view isn't displaying the username.

Do I have to implement a custom adapter?
Is there a quick fix?

Answer 1

I found an answer on the Parse Help Forum:

ParseQueryAdapter setTextKey for relational object

The accepted answer says to use a custom ParseQueryAdapter<T> and Override the getItemView .

For example, in my Fragment's onCreateView method, I initialized the adapter and set it ( postsObjectIds is some String[] ):

PostViewListViewAdapter adapter = new PostViewListViewAdapter(getActivity(), postsObjectIds);

ListView listView = (ListView) rootView.findViewById(R.id.post_list_view);
listView.setAdapter(adapter);

Here's my adapter ( PostViewListViewAdapter ):

public class PostViewListViewAdapter extends ParseQueryAdapter<Post> {

    private final String[] mPostsObjectIds;

    public PostViewListViewAdapter(Context context, final String[] postsObjectIds) {
        super(context, new ParseQueryAdapter.QueryFactory<Post>(){
            public ParseQuery<Post> create() {
                ParseQuery<Post> query = Post.getQuery();
                query.include("User");

                query.whereContainedIn("objectId", Arrays.asList(postsObjectIds));
                return query;
            }
        });
        this.mPostsObjectIds = postsObjectIds;
    }

    @Override
    public View getItemView(Post post, View v, ViewGroup parent) {
        if(v == null) {
            v = View.inflate(getContext(), R.layout.list_item_post_view, null);
        }

        super.getItemView(post, v, parent);

        final TextView usernameTextView = (TextView) v.findViewById(R.id.username_text_view);

        post.getCreator().fetchIfNeededInBackground(new GetCallback<ParseUser>() {
            @Override
            public void done(ParseUser user, ParseException e) {
                usernameTextView.setText(user.getUsername());
            }
        });
        return v;
    }
}