使用Firebase中的数据显示片段上的RecyclerView

Question

我在使用RecycleViewFirebase中的数据创建片段时遇到问题.我希望应用程序显示RecycleView我点击按钮后从一个片段更改为RecycleView片段,但它确实更改了显示的片段,但它没有显示任何内容.

我知道有很多这样的问题,但我似乎没有找到解决这个问题的正确方法.

我已经完成了Firebase RecyclerView所需的一切,并且还尝试在一个活动而不是片段中构建它,它确实有效,但不是片段.我试图在onCreateView方法,onActivityCreated和onViewCreated方法中初始化适配器和recyclerview,但它们似乎都没有工作.

这是我的片段代码:

private KidAdapter adapter;
private RecyclerView recyclerView;

Button button;
View view;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    view = inflater.inflate(R.layout.uangsaku_menu_fragment, container, false);
    button = view.findViewById(R.id.btn_add);
    button.setOnClickListener(this);

    recyclerView = view.findViewById(R.id.recyclerView);
    recyclerView.setHasFixedSize(true);
    setUpRecyclerView();

    return view;
}

@Override
public void onClick(View v) {
    if(v.getId() == R.id.btn_add){
        Intent intent = new Intent(getActivity(), Register.class);
        startActivity(intent);
    }

}

public void setUpRecyclerView(){
    Query query = FirebaseDatabase.getInstance().getReference("kids");

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

    adapter = new KidAdapter(options);
    LinearLayoutManager linearLayoutManager = new LinearLayoutManager(getContext(), LinearLayoutManager.HORIZONTAL, false);
    recyclerView.setLayoutManager(linearLayoutManager);
    recyclerView.setAdapter(adapter);
}

@Override
public void onStart() {
    super.onStart();
    if (adapter != null) {
        adapter.startListening();
    }

}

@Override
public void onStop() {
    super.onStop();
    if (adapter != null) {
        adapter.stopListening();
    }

}

}

适配器类

public class KidAdapter extends FirebaseRecyclerAdapter<kidData, KidAdapter.KidViewHolder> {

public KidAdapter(@NonNull FirebaseRecyclerOptions<kidData> options) {
    super(options);
}

@Override
protected void onBindViewHolder(@NonNull KidViewHolder holder, int position, @NonNull kidData model) {
    holder.nama.setText(model.getKidName());
    holder.balance.setText(model.getKidBalance());
    holder.limit.setText("Limit: "+model.getKidLimit());
    holder.spending.setText("Spending xxx.xxx");
}

@NonNull
@Override
public KidViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
    View v = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.kids_card,
            viewGroup, false);
    return new KidViewHolder(v);
}

public class KidViewHolder extends RecyclerView.ViewHolder {

    TextView nama, balance, limit, spending;
    public KidViewHolder(@NonNull View itemView) {
        super(itemView);

        nama = itemView.findViewById(R.id.tv_nama);
        balance = itemView.findViewById(R.id.tv_balance);
        limit = itemView.findViewById(R.id.tv_dailylimit);
        spending = itemView.findViewById(R.id.tv_dailyspending);
    }
}

}

kidData模型类

public class kidData {
String kidName, kidEmail, kidDoB, kidLimit, kidBalance;

public kidData(){

}

public kidData(String kidName, String kidEmail, String kidDoB, String kidLimit, String kidBalance) {
    this.kidName = kidName;
    this.kidEmail = kidEmail;
    this.kidDoB = kidDoB;
    this.kidLimit = kidLimit;
    this.kidBalance = kidBalance;
}

public String getKidName() {
    return kidName;
}

public String getKidEmail() {
    return kidEmail;
}

public String getKidDoB() {
    return kidDoB;
}

public String getKidLimit() {
    return kidLimit;
}

public String getKidBalance() {
    return kidBalance;
}

}

Answer 1

您代码中的问题是使用了以下代码行：

recyclerView.setHasFixedSize(true);

这是因为在使用最新版本的Firebase-UI库时，不需要将大小设置RecyclerView为固定。解决这个问题的解决方案是简单地删除/注释上面的代码行。就是这样！