我如何在Android Studio上禁用Facebook的注销按钮？

Question

我是android studio的初学者，我正在尝试使用以下内容创建应用。我已经创建了应用程序的第一部分（登录），并且运行良好，但是当我尝试登录以向我显示注销按钮时，我并不需要。我只想在第二个活动中显示Google地图。 在第二个活动中，我尝试显示一个按钮，但没有出现。我该怎么做才能显示地图而不显示注销按钮？

原谅我语法错误。

package com.nikos.findme;

import android.content.Intent;
import android.support.annotation.NonNull;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

import com.facebook.AccessToken;
import com.facebook.CallbackManager;
import com.facebook.FacebookCallback;
import com.facebook.FacebookException;
import com.facebook.FacebookSdk;
import com.facebook.login.LoginManager;
import com.facebook.login.LoginResult;
import com.facebook.login.widget.LoginButton;
import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.auth.AuthCredential;
import com.google.firebase.auth.AuthResult;
import com.google.firebase.auth.FacebookAuthProvider;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;

import java.util.Arrays;

public class MainActivity extends AppCompatActivity {

    private CallbackManager mCallbackManager;
    private static  final String TAG="FACELOG";
    private FirebaseAuth mAuth;


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

        // Initialize Firebase Auth
        mAuth = FirebaseAuth.getInstance();


        // Initialize Facebook Login button
        mCallbackManager = CallbackManager.Factory.create();
        LoginButton loginButton = (LoginButton) findViewById(R.id.login_button);


        loginButton.setReadPermissions("email", "public_profile");
        loginButton.registerCallback(mCallbackManager, new FacebookCallback<LoginResult>() {
            @Override
            public void onSuccess(LoginResult loginResult) {
                Log.d(TAG, "facebook:onSuccess:" + loginResult);
                handleFacebookAccessToken(loginResult.getAccessToken());
            }

            @Override
            public void onCancel() {
                Log.d(TAG, "facebook:onCancel");
            }

            @Override
            public void onError(FacebookException error) {
                Log.d(TAG, "facebook:onError", error);
            }
        });

        //FirebaseAuth.getInstance().signOut();
    }
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        // Pass the activity result back to the Facebook SDK
        mCallbackManager.onActivityResult(requestCode, resultCode, data);
    }

    @Override
    public void onStart() {
        super.onStart();
        // Check if user is signed in (non-null) and update UI accordingly.
        FirebaseUser currentUser = mAuth.getCurrentUser();
        if(currentUser!=null){
            updateUI();
        }
    }

    private void updateUI() {
        Toast.makeText(MainActivity.this,"You are logged in!",Toast.LENGTH_LONG).show();
        //FacebookSdk.sdkInitialize(getApplicationContext());
        Intent intent=new Intent(this,Main2Activity.class);
        //LoginManager.getInstance().logOut();
        startActivity(intent);
        finish();
    }

    private void handleFacebookAccessToken(AccessToken token) {
        Log.d(TAG, "handleFacebookAccessToken:" + token);

        AuthCredential credential = FacebookAuthProvider.getCredential(token.getToken());
        mAuth.signInWithCredential(credential)
                .addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
                    @Override
                    public void onComplete(@NonNull Task<AuthResult> task) {
                        if (task.isSuccessful()) {
                            // Sign in success, update UI with the signed-in user's information
                            Log.d(TAG, "signInWithCredential:success");
                            FirebaseUser user = mAuth.getCurrentUser();
                        } else {
                            // If sign in fails, display a message to the user.
                            Log.w(TAG, "signInWithCredential:failure", task.getException());
                            Toast.makeText(MainActivity.this, "Authentication failed.",Toast.LENGTH_SHORT).show();
                        }
                    }
                });
    }
}