java - Firebase UI更新后无法使Viewholder最终化

我将com.firebaseui:firebase-ui-database软件包从1.1.1更新为3.3.1。看来我不能在FirebaseRecyclerAdapter中使用populateViewHolder了。相反，我应该使用onBindViewHolder。我认为这很好，但是当我从内部类（另一个数据库Ref）中调用viewholder时，我需要使viewholder最终化，这时适配器会给出以下错误：



编码

addedFriendsRecycleViewAdapter = new FirebaseRecyclerAdapter<Boolean, SingleImageViewHolder>(
      Boolean.class,
      R.layout.adduser_single_round_pictrure_layout,
      SingleImageViewHolder.class,
      mMembersDatabase
) {
      @Override
      public SingleImageViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
          return null;
      }

      @Override
      protected void onBindViewHolder(@NonNull final SingleImageViewHolder holder, int position, @NonNull Boolean model) {
          final String added_list_user_id = getRef(position).getKey();

          mUsersDatabase.child(added_list_user_id).addValueEventListener(new ValueEventListener() {
              @Override
              public void onDataChange(DataSnapshot dataSnapshot) {

                  String userThumb = dataSnapshot.child("thumb_image").getValue().toString();

                  holder.setImage(userThumb, AddUserActivity.this);

              }

              @Override
              public void onCancelled(DatabaseError databaseError) {

              }
          });
      }
  };

最佳答案

您需要在3.0+版本中使用FirebaseRecyclerOptions：


  首先，通过构建FirebaseRecyclerOptions配置适配器：

 FirebaseRecyclerOptions<POJO> options =
            new FirebaseRecyclerOptions.Builder<POJO>()
                    .setQuery(query, POJO.class)
                    .build();

  接下来创建FirebaseRecyclerAdapter对象：

FirebaseRecyclerAdapter adapter = new FirebaseRecyclerAdapter<POJO, SingleImageViewHolder>(options) {
@Override
public SingleImageViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    // Create a new instance of the ViewHolder, in this case we are using a custom
    // layout called R.layout.message for each item
    View view = LayoutInflater.from(parent.getContext())
            .inflate(R.layout.message, parent, false);

    return new SingleImageViewHolder(view);
}

@Override
protected void onBindViewHolder(SingleImageViewHolder holder, int position, POJO model) {
    // Bind the Chat object to the ChatHolder
    // ...
   }
};

此处有更多详细信息：

https://github.com/firebase/FirebaseUI-Android/tree/master/database