Question

获取数据：

    private void fetchResults() {
    mDatabaseReference.child("Users").child(id).child("Quiz").child("Results").child(id).addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
            for (DataSnapshot resultSnapshot: dataSnapshot.getChildren()) {
                String user = resultSnapshot.getKey();
                String score = resultSnapshot.getValue(String.class);
                Results results = new Results(user, score);
                resultsList.add(results);
            }
            mAdapter.notifyDataSetChanged();

                    }

        @Override
        public void onCancelled(DatabaseError databaseError) {
            throw databaseError.toException();
        }
    });
}

保存数据：

 String name = RecieversName;
                HashMap<String, String> userMap = new HashMap<>();
                userMap.put(name, String.valueOf(mScore));
                mRef.child("Users").child(RecieversId).child("Quiz").child("Results").child(UID).setValue(userMap).addOnCompleteListener(new OnCompleteListener<Void>() {
                    @Override
                    public void onComplete(@NonNull Task<Void> task) {
                        if (task.isSuccessful()) {
                            Intent intent = new Intent(TakingQuiz.this, TakingQuizDone.class);
                            intent.putExtra("RecieversId",RecieversId);
                            intent.putExtra("Score", mScore.toString());
                            startActivity(intent);
                            finish();
                        }
                    }
                });

适配器：

public class AdapterQuiz extends RecyclerView.Adapter<AdapterQuiz.ResultViewHolder>{

private FirebaseAuth mAuth;
private List<Results> mResultsList;

public AdapterQuiz(List<Results>mResultsList)

    {
    this.mResultsList = mResultsList;
    }

public class ResultViewHolder extends RecyclerView.ViewHolder{
public TextView name;
public TextView score;
public ResultViewHolder(View view)
{
    super(view);
    name = (TextView)view.findViewById(R.id.name);
    score = (TextView)view.findViewById(R.id.score);
}
}
@Override
public ResultViewHolder onCreateViewHolder(ViewGroup parent, int viewType)
{
    View V = LayoutInflater.from(parent.getContext()).inflate(R.layout.custom_activity_results,parent,false);
    mAuth = FirebaseAuth.getInstance();
    return new ResultViewHolder(V);
}


@Override
public void onBindViewHolder(ResultViewHolder holder, int position) {

    Results results = mResultsList.get(position);

    holder.name.setText(results.getName());
    holder.score.setText(results.getScore());
}


@Override
public  int getItemCount() {
    return mResultsList.size();
}

}

结果类

public class Results {
private String Name;
private String Score;

public Results() {
}

public Results(String Name, String Score) {
    this.Name = Name;
    this.Score = Score;
}

public String getName() {
    return Name;
}

public void setName(String name) {
    Name = name;
}

public String getScore() {
    return Score;
}

public void setScore(String score) {
    Score = score;
}

}

我在RecyclerView和Firebase上工作了很长时间，但通常我会显示一个常量'name'和一个变量'value'，但这里的名字和变量都不是我决定的......当用户完成测验时他的得分将显示在recyclerview中，但它只显示空白而没有任何错误...我不确定这是否是获取此类数据的正确方法...任何人都可以帮助我

数据库 - https://ibb.co/eMWkFJ

Answer 1

import re
p = re.compile(ac_name + '\s*')
["" if not kv else kv[0].split('=')[-1].strip() for kv in  [filter(lambda x: p.match(x), xs) for xs in datas]]

我希望这能完成你的工作。

Answer 2

要解决此问题，首先需要先设置适配器，然后再通知它。所以请使用以下代码行：

mRecyclerView.setAdapter(mAdapter);

而不是：

mAdapter.notifyDataSetChanged();

只有在数据库中发生某些更改并且为了通知适配器时，才应使用最后一行代码，这必须在第一步设置。

如何在RecyclerView中显示firebase数据库的变量“name”和“value”

2 个答案: