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Sophie Alpert
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<!DOCTYPE html><html lang="en"><head><meta charSet="utf-8"/><meta http-equiv="X-UA-Compatible" content="IE=edge"/><title>BackHandler · React Native</title><meta name="viewport" content="width=device-width"/><meta name="generator" content="Docusaurus"/><meta name="description" content="Detect hardware button presses for back navigation."/><meta name="docsearch:version" content="0.13"/><meta name="docsearch:language" content="en"/><meta property="og:title" content="BackHandler · React Native"/><meta property="og:type" content="website"/><meta property="og:url" content="https://facebook.github.io/react-native/index.html"/><meta property="og:description" content="Detect hardware button presses for back navigation."/><meta name="twitter:card" content="summary"/><link rel="shortcut icon" href="/react-native/img/favicon.png"/><link rel="stylesheet" href="https://cdn.jsdelivr.net/docsearch.js/1/docsearch.min.css"/><link rel="stylesheet" href="//cdnjs.cloudflare.com/ajax/libs/highlight.js/9.12.0/styles/solarized-dark.min.css"/><link rel="alternate" type="application/atom+xml" href="https://facebook.github.io/react-native/blog/atom.xml" title="React Native Blog ATOM Feed"/><link rel="alternate" type="application/rss+xml" href="https://facebook.github.io/react-native/blog/feed.xml" title="React Native Blog RSS Feed"/><script>
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</script><script type="text/javascript" src="https://snack.expo.io/embed.js"></script><script type="text/javascript" src="/react-native/js/codeblocks.js"></script><link rel="stylesheet" href="/react-native/css/main.css"/></head><body class="sideNavVisible"><div class="fixedHeaderContainer"><div class="headerWrapper wrapper"><header><a href="/react-native/"><img class="logo" src="/react-native/img/header_logo.png" alt="React Native"/><h2 class="headerTitleWithLogo">React Native</h2></a><a href="/react-native/versions"><h3>0.13</h3></a><div class="navigationWrapper navigationSlider"><nav class="slidingNav"><ul class="nav-site nav-site-internal"><li class=""><a href="/react-native/docs/0.13/getting-started" target="_self">Docs</a></li><li class=""><a href="/react-native/en/help" target="_self">Community</a></li><li class=""><a href="/react-native/blog" target="_self">Blog</a></li><li class="navSearchWrapper reactNavSearchWrapper"><input type="text" id="search_input_react" placeholder="Search" title="Search"/></li><li class=""><a href="https://github.com/facebook/react-native" target="_self">GitHub</a></li><li class=""><a href="https://reactjs.org/" target="_self">React</a></li></ul></nav></div></header></div></div><div class="navPusher"><div class="docMainWrapper wrapper"><div class="container mainContainer"><div class="wrapper"><div class="post"><header class="postHeader"><a class="edit-page-link button" href="https://github.com/facebook/react-native-website/blob/master/docs/backhandler.md" target="_blank" rel="noreferrer noopener">Edit</a><h1 class="postHeaderTitle">BackHandler</h1></header><article><div><span><p>Detect hardware button presses for back navigation.</p>
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<p><strong>Android:</strong> 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.</p>
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<p><strong>tvOS:</strong> 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.</p>
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<p><strong>iOS:</strong> Not applicable.</p>
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<p>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.</p>
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<p>Example:</p>
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<pre><code class="hljs css languages- javascript">BackHandler.addEventListener(<span class="hljs-string">'hardwareBackPress'</span>, <span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params"></span>) </span>{
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<span class="hljs-comment">// this.onMainScreen and this.goBack are just examples, you need to use your own implementation here</span>
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<span class="hljs-comment">// Typically you would use the navigator here to go to the last state.</span>
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<span class="hljs-keyword">if</span> (!<span class="hljs-keyword">this</span>.onMainScreen()) {
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<span class="hljs-keyword">this</span>.goBack();
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<span class="hljs-keyword">return</span> <span class="hljs-literal">true</span>;
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}
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<span class="hljs-keyword">return</span> <span class="hljs-literal">false</span>;
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});
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</code></pre>
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<h3><a class="anchor" aria-hidden="true" id="methods"></a><a href="#methods" aria-hidden="true" class="hash-link"><svg class="hash-link-icon" aria-hidden="true" height="16" version="1.1" viewBox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"></path></svg></a>Methods</h3>
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<ul>
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<li><a href="/react-native/docs/0.13/backhandler#exitapp"><code>exitApp</code></a></li>
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<li><a href="/react-native/docs/0.13/backhandler#addeventlistener"><code>addEventListener</code></a></li>
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<li><a href="/react-native/docs/0.13/backhandler#removeeventlistener"><code>removeEventListener</code></a></li>
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</ul>
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<hr>
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<h1><a class="anchor" aria-hidden="true" id="reference"></a><a href="#reference" aria-hidden="true" class="hash-link"><svg class="hash-link-icon" aria-hidden="true" height="16" version="1.1" viewBox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"></path></svg></a>Reference</h1>
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<h2><a class="anchor" aria-hidden="true" id="methods-1"></a><a href="#methods-1" aria-hidden="true" class="hash-link"><svg class="hash-link-icon" aria-hidden="true" height="16" version="1.1" viewBox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"></path></svg></a>Methods</h2>
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<h3><a class="anchor" aria-hidden="true" id="exitapp"></a><a href="#exitapp" aria-hidden="true" class="hash-link"><svg class="hash-link-icon" aria-hidden="true" height="16" version="1.1" viewBox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"></path></svg></a><code>exitApp()</code></h3>
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<pre><code class="hljs css languages- javascript">BackHandler.exitApp();
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</code></pre>
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<hr>
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<h3><a class="anchor" aria-hidden="true" id="addeventlistener"></a><a href="#addeventlistener" aria-hidden="true" class="hash-link"><svg class="hash-link-icon" aria-hidden="true" height="16" version="1.1" viewBox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"></path></svg></a><code>addEventListener()</code></h3>
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<pre><code class="hljs css languages- javascript">BackHandler.addEventListener(eventName, handler);
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</code></pre>
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<hr>
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<h3><a class="anchor" aria-hidden="true" id="removeeventlistener"></a><a href="#removeeventlistener" aria-hidden="true" class="hash-link"><svg class="hash-link-icon" aria-hidden="true" height="16" version="1.1" viewBox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"></path></svg></a><code>removeEventListener()</code></h3>
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<pre><code class="hljs css languages- javascript">BackHandler.removeEventListener(eventName, handler);
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</code></pre>
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