FingerPrint.js

import React, { Component } from 'react';
import {
  AlertIOS,
  StyleSheet,
  Text,
  TouchableHighlight,
  View,
  NativeModules
} 
import TouchID from 'react-native-touch-id'

class FingerPrint extends React.Component {
	
  //config is optional to be passed in on Android
  const optionalConfigObject = {
   title: "Authentication Required", // Android
   color: "#e00606", // Android,
   fallbackLabel: "Show Passcode" // iOS (if empty, then label is hidden)
 }

  pressHandler() {
    TouchID.authenticate('to demo this react-native component', optionalConfigObject)
      .then(success => {
        AlertIOS.alert('Authenticated Successfully');
      })
      .catch(error => {
        AlertIOS.alert('Authentication Failed');
      });
  }
	
  render() {
    return (
      <View>
        <TouchableHighlight onPress={this.pressHandler}>
          <Text>
            Authenticate with Touch ID
          </Text>
        </TouchableHighlight>
      </View>
    );
  }
};