Question

我生气了，这段代码工作了一段时间，现在它不是......通过调试器一切正常但是当我刷新我的数据库时我什么也看不见.... 问题是它没有上传到数据库。

规则设置为

“。read”：“true”， “.write”：“true”

public class MainViewFragment extends Fragment {
    private static final String TAG = "MainViewFragment";
    private RecyclerView mView;
    private List<Product> mProducts;
    private DatabaseReference mRef;


    public MainViewFragment() {
        mRef = FirebaseDatabase.getInstance().getReference();
        Product pr = new Product("title","price");
        mRef.child("products").child(pr.getStringId()).setValue(pr);

    }


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View v = inflater.inflate(R.layout.fragment_main_view, container, false);
        mView = (RecyclerView)v.findViewById(R.id.mainViewRecyclerView);


        mProducts = new ArrayList<>();
        mView.setLayoutManager(new LinearLayoutManager(getActivity(),LinearLayoutManager.HORIZONTAL,false));
        MainViewAdapter adapter = new MainViewAdapter(mProducts,getActivity());
        mView.setAdapter(adapter);
        return v;
    }

    @Override
    public void onAttach(Context context) {
        super.onAttach(context);
    }
}

从这里调用片段

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        FragmentManager fm = getSupportFragmentManager();
        fm.beginTransaction().replace(R.id.container,new MainViewFragment()).commit();
        fm.beginTransaction().replace(R.id.container2,new SecondProductFragment()).commit();

在调试器中，代码尝试setValue（）后，它会给我这个错误

没有这样的实例字段：'mRef'

Answer 1

转到此链接：

https://console.firebase.google.com/project/note-it-b6f1c/database/note-it-b6f1c/rules

并将规则设置为：

 {
   "rules": {
   "foo": {
   ".read": true,
   ".write": true
   }
 }

这可能会解决您的问题

Answer 2

尝试使用地图保存您的数据。

所以替换这个：

     public MainViewFragment() {
     mRef = FirebaseDatabase.getInstance().getReference();
     Product pr = new Product("title","price");
     mRef.child("products").child(pr.getStringId()).setValue(pr);

     }

用这个

      public MainViewFragment() {
      mRef = FirebaseDatabase.getInstance().getReference().child("products").push();
      //make a map
       Map map=new HashMap();
       map.put("title","any_title");
       map.put("price","any_price");
       //write the data
       mRef.setValue(map);

       }

并确保调用（MainViewFragment（））。

Firebase数据库无法上传值

2 个答案: