react-native/docs/backhandler.md

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---
id: backhandler
title: BackHandler
layout: docs
category: APIs
permalink: docs/backhandler.html
next: cameraroll
previous: backhandler
---
Detect hardware button presses for back navigation.
**Android:** Detect hardware back button presses, and programmatically invoke the default back button functionality to exit the app if there are no listeners or if none of the listeners return true.
**tvOS:** Detect presses of the menu button on the TV remote. Still to be implemented: programmatically disable menu button handling functionality to exit the app if there are no listeners or if none of the listeners return true.
**iOS:** Not applicable.
The event subscriptions are called in reverse order (i.e. last registered subscription first), and if one subscription returns true then subscriptions registered earlier will not be called.
Example:
```javascript
BackHandler.addEventListener('hardwareBackPress', function() {
// this.onMainScreen and this.goBack are just examples, you need to use your own implementation here
// Typically you would use the navigator here to go to the last state.
if (!this.onMainScreen()) {
this.goBack();
return true;
}
return false;
});
```
### Methods
- [`exitApp`](docs/backhandler.html#exitapp)
- [`addEventListener`](docs/backhandler.html#addeventlistener)
- [`removeEventListener`](docs/backhandler.html#removeeventlistener)
---
# Reference
## Methods
### `exitApp()`
```javascript
BackHandler.exitApp()
```
---
### `addEventListener()`
```javascript
BackHandler.addEventListener(eventName, handler)
```
---
### `removeEventListener()`
```javascript
BackHandler.removeEventListener(eventName, handler)
```