动态地将 TextViews 添加到排行榜屏幕

Question

I have a leaderboard screen in my app where i want to add each users score. So far I have been able to retrieve the scores from the the database but I want to show these scores on a leaderboard screen.

I have this code, but the for loop sets the text of the textView and instead of each score being displayed, only the last score of the loop is displayed. Is there anyway to not overwrite the textView and instead have multiple textViews created and displayed?

package com.example.securityapp;

import androidx.appcompat.app.AppCompatActivity;

import android.nfc.Tag;
import android.os.Bundle;
import android.util.Log;
import android.widget.TextView;

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.Query;
import com.google.firebase.database.ValueEventListener;

import static java.lang.System.in;

public class leaderboard extends AppCompatActivity {

    DatabaseReference databaseUsers;
    FirebaseDatabase database = FirebaseDatabase.getInstance();
    FirebaseAuth mAuth;
    TextView score;
    private static final String TAG = "leaderboard";



    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_leaderboard);

        mAuth = FirebaseAuth.getInstance();
        FirebaseUser user = mAuth.getCurrentUser();
        score = (TextView) findViewById(R.id.tableText);


        database.getReference().child("Scores").addValueEventListener(new ValueEventListener() {
            public void onDataChange(DataSnapshot dataSnapshot) {
                for (DataSnapshot snapshot : dataSnapshot.getChildren()) {
                        System.out.println("The score is: " + snapshot.toString());
                        score.setText(snapshot.toString());
                    }
                }


            @Override
            public void onCancelled(DatabaseError databaseError) {
             // Getting Post failed, log a message
             Log.w(TAG, "loadPost:onCancelled", databaseError.toException());

    }


});

        }
}

Answer 1

Just Append the string when the loop starts again

Take A Global Variable String s=" ";

s = s + snapshoot.toString();

Answer 2

you can concat the string everytime but if you want to save them , you can use sharedPrefenrece . First you can save the scores in sharedPreference and everytime that the onDataChanged function is called , you can concat the newScore to the previous scores. like this :

SharedPreference sharedPreference = getSharedPreference("Scores" , MODE_PRIVATE); // in the top of database callback

and in the onDataChanged function :

sharedPreference.edit().putString("score" , sharedPreference.getString("score" , "") + " " + snapShot.toString);