Router.js

import { createStackNavigator } from 'react-navigation-stack';
import { createAppContainer } from 'react-navigation';
import EntryPoint from './UI/EntryPoint';
import appConstants from '../common/AppConstants';


let routes = {}
routes[appConstants.appRoutes.ENTRY_POINT] = { screen: EntryPoint }
const MainNavigator = createStackNavigator(
  routes,
  {
    headerMode: 'none',
    /* The header config from HomeScreen is now here */
    defaultNavigationOptions: {
      headerStyle: {
        backgroundColor: '#f00',
        alignContent: 'center',

      },
      headerTintColor: '#fff',
      headerTitleStyle: {
        fontWeight: 'bold',
        marginLeft: 0
      },
    },
  }
);


const Router = createAppContainer(MainNavigator);

export default Router;