Can't change text of TextView Android

Question

Can't change Welcome TextView. I need help. See the code below:

I am developing new app android with facebook login.

I edit again to show all the code...

package app.android.listasvip;

import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;

import android.app.Activity;
import android.content.Intent;
import android.widget.TextView;
import com.facebook.*;
import com.facebook.model.*;

public class MainActivity extends ActionBarActivity {

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

        if (savedInstanceState == null) {
            getSupportFragmentManager().beginTransaction().add(R.id.container, new PlaceholderFragment()).commit();
        }

        // start Facebook Login
        Session.openActiveSession(this, true, new Session.StatusCallback() {

            // callback when session changes state
            @Override
            public void call(Session session, SessionState state, Exception exception) {
                if (session.isOpened()) {
                    // make request to the /me API
                    Request.newMeRequest(session, new Request.GraphUserCallback() {

                        // callback after Graph API response with user object
                        @Override
                        public void onCompleted(GraphUser user, Response response) {
                            if (user != null) {
                                TextView welcome = (TextView) findViewById(R.id.welcome);
                                welcome.setText("Hello " + user.getName() + "!");
                            }
                        }
                    }).executeAsync();
                }
            }
        });
    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (Session.getActiveSession() != null) {
            Session.getActiveSession().onActivityResult(this, requestCode, resultCode, data);
        }
        super.onActivityResult(requestCode, resultCode, data);  
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            TextView welcome = (TextView) findViewById(R.id.welcome);
            welcome.setText("Configurações");
        }
        return super.onOptionsItemSelected(item);
    }

    /**
     * A placeholder fragment containing a simple view.
     */
    public static class PlaceholderFragment extends Fragment {

        public PlaceholderFragment() {
        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.fragment_main, container, false);
            return rootView;
        }
    }

}

Answer 1

You have to execute your Request with executeAsync(). Otherwise it will not execute:

    Session.openActiveSession(this, true, new Session.StatusCallback() {
    // callback when session changes state
    @Override
    public void call(Session session, SessionState state, Exception exception) {
        if (session.isOpened()) {
            // make request to the /me API
            Request.newMeRequest(session, new Request.GraphUserCallback() {

                @Override
                public void onCompleted(GraphUser user, Response response) {                            
                    if (user != null) {
                        TextView welcome = (TextView) findViewById(R.id.welcome);
                        welcome.setText("Olá "+user.getName()+"!");
                    }
                }
            }).executeAsync();
        }
    }
});

Overwrite onActivityResult in your Activity with:

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (Session.getActiveSession() != null) {
        Session.getActiveSession().onActivityResult(this, requestCode,
                resultCode, data);
    }
    super.onActivityResult(requestCode, resultCode, data);
}