App.js

import {createAppContainer} from 'react-navigation'
import {createStackNavigator} from 'react-navigation-stack'
import React from 'react';
import { Provider } from './src/screens/context/BlogContext'
import IndexScreen from './src/screens/IndexScreen';
import ShowScreen from './src/screens/ShowScreen';
import CreateScreen from './src/screens/CreateScreen';
import EditScreen from './src/screens/EditScreen';

const navigator = createStackNavigator({
  Index: IndexScreen,
  Show: ShowScreen,
  Create: CreateScreen,
  Edit: EditScreen
}, {
  initialRouteName: 'Index',
  defaultNavigationOptions : {
    title: 'Blogs'
  }
})

const App = createAppContainer(navigator);

export default () => {
  return( 
    <Provider>
      <App/>
    </Provider>
  )
}