пересылка данных во Fragment

Код данной активити получает ответ от сервера и по задумке должен отправить результат во фрагмент.

public void Okhhtp(){

        OkHttpClient client = new OkHttpClient();
        Request request = new Request.Builder()
                .url(link)
                .build();
        Call call = client.newCall(request);
        call.enqueue(new
        Callback() {
            @Override
            public void onFailure (Call call, IOException e){
                Toast.makeText(MainActivity.this, "Text loaded", Toast.LENGTH_SHORT).show();
            }
            @Override
            public void onResponse (Call call, Response response) throws IOException {
              final String result = response.body().string();
                MainActivity.this.runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        Bundle bundle = new Bundle();
                        bundle.putString("a", result);
                        dialogFragment.setArguments(bundle);
                        Toast.makeText(MainActivity.this,result, Toast.LENGTH_SHORT).show();
                    }
                });
            }
        });

    }

ответ от сервера пришел, об этом говорит "тост" содержащий ответ сервера, фрагмент открылся, об этом говорит текст вью отображающееся на экране, но содержимое ответа не передается во фрагмент.. в текст вью.

код Fragment

public class DialogFragment extends Fragment {
        String b;
    TextView text;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_dialog, container, false);
        text = (TextView)view.findViewById(R.id.textView3);



        Bundle bundle = this.getArguments();
        if (bundle != null) {
            b = bundle.getString("a");
            text.setText(b);

        }
        return view;
    }

Кусок кода открытия фрагмента

if (id == R.id.nav_camera) {
            fragmentClass = DialogFragment.class;
            try {
                Okhhtp();
            } catch (Exception e) {
                e.printStackTrace();
            }

весь код главного активити

    public class MainActivity extends AppCompatActivity
        implements NavigationView.OnNavigationItemSelectedListener {
    com.witryna.Fragment.DialogFragment dialogFragment = new com.witryna.Fragment.DialogFragment();
    public String a = "gfgf";
    OkHttpClient client = new OkHttpClient();
    ArrayList<Sdialog> UpList = new ArrayList<>();
  Bundle bundle= new Bundle();
ProfilFragment profilFragment = new ProfilFragment();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        //FragmentManager fragmentManager = getSupportFragmentManager();
        //fragmentManager.beginTransaction()          // получаем экземпляр FragmentTransaction
                //.replace(R.id.container, dialogFragment).commit();            // вызываем commit для совершения действий FragmentTransaction

        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                        .setAction("Action", null).show();
            }
        });
        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
                this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
        drawer.setDrawerListener(toggle);
        toggle.syncState();
        NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
        navigationView.setNavigationItemSelectedListener(this);
        //bundle = new Bundle();
    }
    @Override
    public void onBackPressed() {
        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        if (drawer.isDrawerOpen(GravityCompat.START)) {
            drawer.closeDrawer(GravityCompat.START);
        } else {
            super.onBackPressed();
        }
    }
    @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();
        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }
    @SuppressWarnings("StatementWithEmptyBody")
    @Override
    public boolean onNavigationItemSelected(MenuItem item) {
        Fragment fragment = null;
        Class fragmentClass = null;
        // Handle navigation view item clicks here.
        int id = item.getItemId();
        if (id == R.id.nav_camera) {
            fragmentClass = com.witryna.Fragment.DialogFragment.class;
            try {
                Okhhtp();
            } catch (Exception e) {
                e.printStackTrace();
            }

        } else if (id == R.id.nav_gallery) {
            fragmentClass = ProfilFragment.class;
            try {
                Okhhtp();
            } catch (Exception e) {
                e.printStackTrace();
            }
        } else if (id == R.id.nav_slideshow) {
            fragmentClass = DialogFragment.class;
        } else if (id == R.id.nav_manage) {
            fragmentClass = DialogFragment.class;
        } else if (id == R.id.nav_share) {
            fragmentClass = DialogFragment.class;
        } else if (id == R.id.nav_send) {
            fragmentClass = DialogFragment.class;
        }
        try {
            fragment = (Fragment) fragmentClass.newInstance();
        } catch (Exception e) {
            e.printStackTrace();
        }
        // Вставляем фрагмент, заменяя текущий фрагмент
        FragmentManager fragmentManager = getSupportFragmentManager();
        fragmentManager.beginTransaction().replace(R.id.container, fragment).commit();
        // Выделяем выбранный пункт меню в шторке
        item.setChecked(true);
        // Выводим выбранный пункт в заголовке
        setTitle(item.getTitle());
        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        drawer.closeDrawer(GravityCompat.START);
        return true;
    }

  public void Okhhtp(){

        OkHttpClient client = new OkHttpClient();
        Request request = new Request.Builder()
                .url("http://123.party/")
                .build();
        Call call = client.newCall(request);
        call.enqueue(new
        Callback() {
            @Override
            public void onFailure (Call call, IOException e){
                Toast.makeText(MainActivity.this, "Text loaded", Toast.LENGTH_SHORT).show();
            }
            @Override
            public void onResponse (Call call, Response response) throws IOException {
              final String result = response.body().string();
                MainActivity.this.runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                       // Bundle bundle = new Bundle();
                       // bundle.putString("a", result);
                        //dialogFragment.setArguments(bundle);
                        dialogFragment.setResult(result);
                        Toast.makeText(MainActivity.this,result, Toast.LENGTH_SHORT).show();
                    }
                });
            }
        });

    }

}

Что я делаю не правильно ?