如何获取我的数据库值并显示在微调器中供用户选择？

Question

这是我的Java页面

package com.example.myfyp;

import android.Manifest;
import android.bluetooth.BluetoothAdapter;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.media.AudioManager;
import android.os.Build;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.Spinner;
import android.widget.TextView;

import androidx.annotation.NonNull;
import androidx.annotation.RequiresApi;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;

import com.example.myfyp.Interface.IFirebaseLoadDone;
import com.example.myfyp.Model.UserID;
import com.google.firebase.FirebaseApp;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ValueEventListener;

import java.util.ArrayList;
import java.util.List;

public class Homepage extends AppCompatActivity implements AdapterView.OnItemSelectedListener {

    Button b1, b2, btnlogout;
    AudioManager am;
    private FirebaseAuth mAuth;
    private FirebaseAuth.AuthStateListener mAuthStateListener;
    TextView newName;
    DatabaseReference databaseReference;
    //SearchableSpinner searchableSpinner;
    Spinner spinner;
    IFirebaseLoadDone iFirebaseLoadDone;
    FirebaseDatabase database;
    List<UserID> movies;
    TextView tvtesting;
    BluetoothAdapter mBluetoothAdapter;

    ArrayList<String> arrayList = new ArrayList<>();


    public void onItemSelected(AdapterView<?> parent, View view, int pos, long id) {
    }

    public void onNothingSelected(AdapterView<?> parent) {
    }

    private Button pass;
    private Button num;
    private Button track;
    private Button power;

    @RequiresApi(api = Build.VERSION_CODES.P)

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_homepage);
        b1 = (Button) findViewById(R.id.vibrate);
        b2 = (Button) findViewById(R.id.normal);
        btnlogout = (Button) findViewById(R.id.logout);
        newName = findViewById(R.id.textView);
        tvtesting = findViewById(R.id.testing);

        spinner = (Spinner) findViewById(R.id.selectdevice);

        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.READ_PHONE_STATE) != PackageManager.PERMISSION_GRANTED) {
            ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.READ_PHONE_STATE}, 101);
        }

        FirebaseApp.initializeApp(this);
        database = FirebaseDatabase.getInstance();
        mAuth = FirebaseAuth.getInstance();
        //databaseReference = FirebaseDatabase.getInstance().getReference("User");
        FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
        String useruid = user.getUid();
        databaseReference = FirebaseDatabase.getInstance().getReference().child(useruid).child("name");

        //final DatabaseReference databaseReference = database.getReference(mAuth.getUid());

        //databaseReference = FirebaseDatabase.getInstance().getReference().child("User").child("user_id");
        final ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_dropdown_item, arrayList);
        //iFirebaseLoadDone = this;


        databaseReference.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                try {
                    UserID userID = dataSnapshot.getValue(UserID.class);
                    arrayList.add(String.valueOf(userID));
                    adapter.notifyDataSetChanged();



                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
            @Override
            public void onCancelled(@NonNull DatabaseError databaseError) {
                throw databaseError.toException();

            }
        });

        spinner.setAdapter(adapter);

        /*databaseReference.addChildEventListener(new ChildEventListener() {

            @Override
            public void onChildAdded(@NonNull DataSnapshot dataSnapshot, @Nullable String s) {
                try {
                    /*String user_id = mAuth.getCurrentUser().getUid();
                    DatabaseReference current_user_db = FirebaseDatabase.getInstance().getReference().child("User").child(user_id);
                    String name = "maybecan";

                    Map newPost = new HashMap();
                    newPost.put("name", name);
                    current_user_db.setValue(newPost);*/

                    /*String onDataChange = dataSnapshot.getValue(String.class).toString();
                    arrayList.add(onDataChange);
                    adapter.notifyDataSetChanged();

                } catch (Exception e) {
                    e.printStackTrace();
                }
            }

            @Override
            public void onChildChanged(@NonNull DataSnapshot dataSnapshot, @Nullable String s) {
                try {
                    adapter.notifyDataSetChanged();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }

            @Override
            public void onChildRemoved(@NonNull DataSnapshot dataSnapshot) {
            }

            @Override
            public void onChildMoved(@NonNull DataSnapshot dataSnapshot, @Nullable String s) {
            }

            @Override
            public void onCancelled(@NonNull DatabaseError databaseError) {
            }
        });*/

        /*databaseReference.addListenerForSingleValueEvent(new ValueEventListener() {
        @Override
        public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                try {
                    List<UserID> movies = new ArrayList<>();
                    for (DataSnapshot movieSnapShot : dataSnapshot.getChildren()) {
                        movies.add(movieSnapShot.getValue(UserID.class));
                    }
                    iFirebaseLoadDone.onFirebaseLoadSuccess(movies);
                }catch (DatabaseException e){
                    e.printStackTrace();
                }
        }

            @Override
            public void onCancelled(@NonNull DatabaseError databaseError) {
                try {
                    iFirebaseLoadDone.onFirebaseLoadFailed(databaseError.getMessage());
                }catch(Exception e){
                    e.printStackTrace();
                }
            }
        });
        */


        /*databaseReference = FirebaseDatabase.getInstance().getReference().child("UserID").child("name");
        databaseReference.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                int i = 0;

                String name = dataSnapshot.child("1").getValue().toString();
                tvtesting.setText(name);
            }

            @Override
            public void onCancelled(@NonNull DatabaseError databaseError) {
            }
        });*/


        //addName();


        //arrayList = new ArrayList<String>();
        //adapter = new ArrayAdapter<String>(Homepage.this, android.R.layout.simple_list_item_1, arrayList);
//try {
    //getBluetoothName();
   // tvtesting.setText(mBluetoothAdapter.agetNme());
//}catch(Exception e){
   // e.printStackTrace();
//}

        am = (AudioManager) getSystemService(Context.AUDIO_SERVICE);

        //1- Vibrate 2-Normal
        b1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                am.setRingerMode(1);
            }
        });
        b2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                am.setRingerMode(2);
            }
        });
/*
try {
    Spinner spinner = (Spinner) findViewById(R.id.selectdevice);
    ArrayAdapter<CharSequence> adapter1 = ArrayAdapter.createFromResource
            (this, R.array.device, android.R.layout.simple_spinner_item);
    adapter1.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    spinner.setAdapter(adapter1);

    Spinner spinner1 = (Spinner) findViewById(R.id.selectdevice);
    spinner.setOnItemSelectedListener(this);
}catch(Exception e){
    e.printStackTrace();
}
*/


        pass = (Button) findViewById(R.id.set_password);
        pass.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                openLock();
            }

        });
        num = (Button) findViewById(R.id.load_number);
        num.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                openNumber();
            }

        });
        track = (Button) findViewById(R.id.track);
        track.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                openTracking();
            }
        });
        power = (Button) findViewById(R.id.gps_power);
        power.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                openGPSPower();
            }
        });
        btnlogout.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                FirebaseAuth.getInstance().signOut();
                openMainActivity();
            }
        });
    }

    @RequiresApi(api = Build.VERSION_CODES.O)

    public void onRequestPermissionResult(int requestCode, String[] permissions, int[] grantResults) {
        switch (requestCode) {
            case 101:
                if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.READ_PHONE_STATE) != PackageManager.PERMISSION_GRANTED) {
                        return;
                    }
                    newName.setText(Build.DEVICE);
                }
                break;
            default:
                super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        }
    }

    @RequiresApi(api = Build.VERSION_CODES.O)
    @Override
    protected void onResume() {
        super.onResume();
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.READ_PHONE_STATE) != PackageManager.PERMISSION_GRANTED) {
            return;
        }
        newName.setText(Build.DEVICE);


    }

    /*public void addName() {
        String name = Build.DEVICE;

        if (TextUtils.isEmpty(name)) {
            Name phoneName = new Name(name);
            databaseReference.child(name).setValue(phoneName);
            Toast.makeText(this, "New name has added", Toast.LENGTH_LONG).show();
        }else{
        Toast.makeText(this, "Error", Toast.LENGTH_LONG).show();
}
    }*/


   /* public String getBluetoothName() {
            if (mBluetoothAdapter == null) {
                mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
            }
            String name = mBluetoothAdapter.getName();
            if (name == null) {
                System.out.println("Name is null!");
                name = mBluetoothAdapter.getAddress();
            }
            return name;
        }*/





    public void openLock() {
        Intent intent = new Intent(this, Lock.class);
        startActivity(intent);
    }
    public void openNumber() {
        Intent intent = new Intent(this, Number.class);
        startActivity(intent);
    }
    public void openTracking() {
        Intent intent = new Intent(this, Tracking.class);
        startActivity(intent);
    }
    public void openGPSPower() {
        Intent intent = new Intent(this, GPSPower.class);
        startActivity(intent);
    }
    public void openMainActivity() {
        Intent intent = new Intent(this, MainActivity.class);
        startActivity(intent);
    }


    /*private boolean addName(String name){

        DatabaseReference databaseReference = FirebaseDatabase.getInstance().getReference("User").child(name);

        UserID userID = new UserID(name);

        databaseReference.setValue(userID);

        Toast.makeText(this, "Successfully", Toast.LENGTH_LONG).show();

        return true;

    }*/




    /*@Override
    public void onFirebaseLoadSuccess(List<UserID> movieList) {
        try {
            movies = movieList;

            List<String> name_list = new ArrayList<>();
            for (UserID movie : movieList)
                name_list.add(movie.getName());
            ArrayAdapter<String> adapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, name_list);
            spinner.setAdapter(adapter);
        }catch(DatabaseException e){
            e.printStackTrace();
        }
    }

    @Override
    public void onFirebaseLoadFailed(String message) {

    }*/
}

这是我的获取数据库值页面

package com.example.myfyp.Model;

public class UserID {
    int sum=0;

    public UserID() {

    }

    public UserID(int sum) {
        //for(int i = 1; i<5;i++){
            //sum += i;
            this.sum = sum;
        //}

    }

    public int getSum() {
        /*for (int i = 1; i < 5; i++) {
            sum += i;
            return sum;
        }*/
        return sum;
    }

    public void setSum(int sum) {
        //for (int i = 1; i < 5; i++) {
            //sum += i;
        //}
        this.sum = sum;
    }

    @Override
    public String toString() {
        //for (int i = 1; i < 5; i++) {
           // sum += i;
        //}
        return "sum=" + sum +
                '}';
    }
}

这是我的firebase数据库界面，显示用户ID以及名称和名称中的值

{
 "9dT4gNOlzEhfeOEvE2Ff7732Dm02" :{
  "name" : ["test1@gmail.com", "try"]
 }
}

因此，当我登录时，应该可以在微调框选择中看到test1@gmail.com和“ try”。但是微调框没有显示任何内容。希望有一些建议可以对我有所帮助。谢谢