App.js

import { AppLoading } from "expo";
import * as Font from "expo-font";
import React from "react";
import { Platform, StatusBar, StyleSheet, View } from "react-native";
import { Ionicons } from "@expo/vector-icons";
import { Root } from "native-base";

import AppNavigator from "./navigation/AppNavigator";
console.ignoredYellowBox = ["Warning: Each", "Warning: Failed"];
console.disableYellowBox = true;
export default class App extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
      isReady: false
    };
  }

  async componentDidMount() {
    await Font.loadAsync({
      Roboto: require("native-base/Fonts/Roboto.ttf"),
      Roboto_medium: require("native-base/Fonts/Roboto_medium.ttf"),
      ...Ionicons.font
    });
    this.setState({ isReady: true });
  }
  render() {
    if (!this.state.isReady) {
      return <AppLoading />;
    } else {
      return (
        <View style={styles.container}>
          {Platform.OS === "ios" && <StatusBar barStyle="default" />}
          <Root>
            <AppNavigator />
          </Root>
        </View>
      );
    }
  }
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: "#fff"
  }
});