CODEWITHSUNDEEP
androidlistenerreact-native
Gabriel Matusevich
Gabriel Matusevich

Reputation: 3855

React Native BackAndroid doesn't remove the listener

I'm adding a new listener to BackAndroid on:

componentWillMount () {
  BackAndroid.addEventListener('hardwareBackPress', backAndroidHandler.bind(this));
}

and I'm removing the listener on:

componentWillUnmount () {
  BackAndroid.removeEventListener('hardwareBackPress', backAndroidHandler);
}

function backAndroidHandler () {
  ...
}

but when I unmount the component and mount it again, there are two of the same function and the same event fires twice. Any clue?

Upvotes: 1

Views: 2489

Answers (2)

I.dev
I.dev

Reputation: 483

this.androidBackHandler = this.backAndroidHandler.bind(this);

It should be like this.

Upvotes: 1

Gabriel Matusevich
Gabriel Matusevich

Reputation: 3855

Fixed it

componentWillMount () {
  this.androidBackHandler = backAndroidHandler.bind(this);
  BackAndroid.addEventListener('hardwareBackPress', this.backAndroidHandler);
}

componentWillUnmount () {
  BackAndroid.removeEventListener('hardwareBackPress', this.androidBackHandler);
}


function backAndroidHandler () {
  ...
}

I tried declaring the function directly on the component but this was not binding, it was undefined

Upvotes: 3

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