---
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)
```