undefined不是对象（评估'_reactNative.BackHandler.addEventListener'）

Question

I am using react-native: 0.40 with react: 15.4.2 and react-native-router-flux: 3.37.0 and I've been getting this error. Although everything I get this error on iOS, the app runs with no issue. But on Android, whenever I press the back button, the app crashes.

My assumption is that react native back button is conflicting with react-native-router-flux package.

Any help would be appreciated.

evaluating '_reactNative.BackHandler.addEventListener'

Answer 1

Try react-native@0.44.0 and react@16.0.0-alpha.6. I believe that this was fixed here: https://github.com/aksonov/react-native-router-flux/pull/1819

I had the same error and after installing the above versions it works for me.

Answer 2

Make sure you are importing BankHandler from react-native and not react, it should be

import { BackHandler } from 'react-native';

NOT

import { BackHandler } from 'react';

That was what caused the error for me :)