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<script src="https://snack.expo.io/embed.js" defer="defer"></script><title data-react-helmet="true">BackHandler · React Native</title><meta data-react-helmet="true" property="twitter:image" content="https://reactnative.dev/img/logo-og.png"><meta data-react-helmet="true" name="twitter:image:alt" content="Image for React Native"><meta data-react-helmet="true" name="docsearch:language" content="en"><meta data-react-helmet="true" name="docsearch:version" content="current"><meta data-react-helmet="true" name="docsearch:docusaurus_tag" content="docs-default-current"><meta data-react-helmet="true" property="og:image" content="https://reactnative.dev/img/logo-og.png"><meta data-react-helmet="true" name="twitter:card" content="summary"><meta data-react-helmet="true" name="twitter:image" content="https://reactnative.dev/img/logo-og.png"><meta data-react-helmet="true" property="og:title" content="BackHandler · React Native"><meta data-react-helmet="true" name="description" content="The Backhandler API detects hardware button presses for back navigation, lets you register event listeners for the system's back action, and lets you control how your application responds. It is Android-only."><meta data-react-helmet="true" property="og:description" content="The Backhandler API detects hardware button presses for back navigation, lets you register event listeners for the system's back action, and lets you control how your application responds. It is Android-only."><meta data-react-helmet="true" property="og:url" content="https://reactnative.dev/docs/next/backhandler"><link data-react-helmet="true" rel="shortcut icon" href="/img/favicon.ico"><link data-react-helmet="true" rel="preconnect" href="https://BH4D9OD16A-dsn.algolia.net" crossorigin="anonymous"><link data-react-helmet="true" rel="canonical" href="https://reactnative.dev/docs/next/backhandler"><link rel="stylesheet" href="/styles.fccefeba.css">
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docItemCol_2AGf"><div class="alert alert--warning margin-bottom--md" role="alert"><div>This is unreleased documentation for React Native <strong>Next</strong> version.</div><div class="margin-top--md">For up-to-date documentation, see the <strong><a href="/docs/backhandler">latest version</a></strong> (0.63).</div></div><div class="docItemContainer_1tAC"><article><div><span class="badge badge--secondary">Version: Next</span></div><header><h1 class="docTitle_cWlf">BackHandler</h1></header><div class="markdown"><p>The Backhandler API detects hardware button presses for back navigation, lets you register event listeners for the system's back action, and lets you control how your application responds. It is Android-only.</p><p>The event subscriptions are called in reverse order (i.e. the last registered subscription is called first).</p><ul><li><strong>If one subscription returns true,</strong> then subscriptions registered earlier will not be called.</li><li><strong>If no subscription returns true or none are registered,</strong> it programmatically invokes the default back button functionality to exit the app.</li></ul><blockquote><p><strong>Warning for modal users:</strong> If your app shows an opened <code>Modal</code>, <code>BackHandler</code> will not publish any events (<a href="/docs/next/modal#onrequestclose">see <code>Modal</code> docs</a>).</p></blockquote><h2><a aria-hidden="true" tabindex="-1" class="anchor enhancedAnchor_3pqN" id="pattern"></a>Pattern<a aria-hidden="true" tabindex="-1" class="hash-link" href="#pattern" title="Direct link to heading">#</a></h2><div class="mdxCodeBlock_xYIz"><div class="codeBlockContent_rlEb"><button tabindex="0" type="button" aria-label="Copy code to clipboard" class="copyButton_kOW4">Copy</button><div class="prism-code language-jsx codeBlock_1AP7"><div class="codeBlockLines_1boI" style="color:#FFFFFF;background:#282C34"><div class="token-line" style="color:#FFFFFF;background:#282C34"><span class="token plain">BackHandler</span><span class="token punctuation" style="color:#657b83">.</span><span class="token function" style="color:#79b6f2">addEventListener</span><span class="token punctuation" style="color:#657b83">(</span><span class="token string" style="color:#8dc891">'hardwareBackPress'</span><span class="token punctuation" style="color:#657b83">,</span><span class="token plain"> </span><span class="token keyword" style="color:#c5a5c5">function</span><span class="token plain"> </span><span class="token punctuation" style="color:#657b83">(</span><span class="token punctuation" style="color:#657b83">)</span><span class="token plain"> </span><span class="token punctuation" style="color:#657b83">{</span><span class="token plain"></span></div><div class="token-line" style="color:#FFFFFF;background:#282C34"><span class="token plain"> </span><span class="token comment" style="color:#93a1a1">/**</span></div><div class="token-line" style="color:#FFFFFF;background:#282C34"><span class="token comment" style="color:#93a1a1"> * this.onMainScreen and this.goBack are just examples,</span></div><div class="token-line" style="color:#FFFFFF;background:#282C34"><span class="token comment" style="color:#93a1a1"> * you need to use your own implementation here.</span></div><div class="token-line" style="color:#FFFFFF;background:#282C34"><span class="token comment" style="color:#93a1a1"> *</span></div><div class="token-line" style="color:#FFFFFF;background:#282C34"><span class="token comment" style="color:#93a1a1"> * Typically you would use the navigator here to go to the last state.</span></div><div class="token-line" style="color:#FFFFFF;background:#282C34"><span class="token comment" style="color:#93a1a1"> */</span><span class="token plain"></span></div><div class="token-line" style="color:#FFFFFF;background:#282C34"><span class="token plain" style="display:inline-block">
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</span></div><div class="token-line" style="color:#FFFFFF;background:#282C34"><span class="token plain"> </span><span class="token keyword" style="color:#c5a5c5">if</span><span class="token plain"> </span><span class="token punctuation" style="color:#657b83">(</span><span class="token operator" style="color:#fc929e">!</span><span class="token keyword" style="color:#c5a5c5">this</span><span class="token punctuation" style="color:#657b83">.</span><span class="token function" style="color:#79b6f2">onMainScreen</span><span class="token punctuation" style="color:#657b83">(</span><span class="token punctuation" style="color:#657b83">)</span><span class="token punctuation" style="color:#657b83">)</span><span class="token plain"> </span><span class="token punctuation" style="color:#657b83">{</span><span class="token plain"></span></div><div class="token-line" style="color:#FFFFFF;background:#282C34"><span class="token plain"> </span><span class="token keyword" style="color:#c5a5c5">this</span><span class="token punctuation" style="color:#657b83">.</span><span class="token function" style="color:#79b6f2">goBack</span><span class="token punctuation" style="color:#657b83">(</span><span class="token punctuation" style="color:#657b83">)</span><span class="token punctuation" style="color:#657b83">;</span><span class="token plain"></span></div><div class="token-line" style="color:#FFFFFF;background:#282C34"><span class="token plain"> </span><span class="token comment" style="color:#93a1a1">/**</span></div><div class="token-line" style="color:#FFFFFF;background:#282C34"><span class="token comment" style="color:#93a1a1"> * When true is returned the event will not be bubbled up</span></div><div class="token-line" style="color:#FFFFFF;background:#282C34"><span class="token comment" style="color:#93a1a1"> * & no other back action will execute</span></div><div class="token-line" style="color:#FFFFFF;background:#282C34"><span class="token comment" style="color:#93a1a1"> */</span><span class="token plain"></span></div><div class="token-line" style="color:#FFFFFF;background:#282C34"><span class="token plain"> </span><span class="token keyword" style="color:#c5a5c5">return</span><span class="token plain"> </span><span class="token boolean" style="color:#ff8b50">true</span><span class="token punctuation" style="color:#657b83">;</span><span class="token plain"></span></div><div class="token-line" style="color:#FFFFFF;background:#282C34"><span class="token plain"> </span><span class="token punctuation" style="color:#657b83">}</span><span class="token plain"></span></div><div class="token-line" style="color:#FFFFFF;background:#282C34"><span class="token plain"> </span><span class="token comment" style="color:#93a1a1">/**</span></div><div class="token-line" style="color:#FFFFFF;background:#282C34"><span class="token comment" style="color:#93a1a1"> * Returning false will let the event to bubble up & let other event listeners</span></div><div class="token-line" style="color:#FFFFFF;background:#282C34"><span class="token comment" style="color:#93a1a1"> * or the system's default back action to be executed.</span></div><div class="token-line" style="color:#FFFFFF;background:#282C34"><span class="token comment" style="color:#93a1a1"> */</span><span class="token plain"></span></div><div class="token-line" style="color:#FFFFFF;background:#282C34"><span class="token plain"> </span><span class="token keyword" style="color:#c5a5c5">return</span><span class="token plain"> </span><span class="token boolean" style="color:#ff8b50">false</span><span class="token punctuation" style="color:#657b83">;</span><span class="token plain"></span></div><div class="token-line" style="color:#FFFFFF;background:#282C34"><span class="token plain"></span><span class="token punctuation" style="color:#657b83">}</span><span class="token punctuation" style="color:#657b83">)</span><span class="token punctuation" style="color:#657b83">;</span></div></div></div></div></div><h2><a aria-hidden="true" tabindex="-1" class="anchor enhancedAnchor_3pqN" id="example"></a>Example<a aria-hidden="true" tabindex="-1" class="hash-link" href="#example" title="Direct link to heading">#</a></h2><p>The following example implements a scenario where you confirm if the user wants to exit the app:</p><div><ul role="tablist" aria-orientation="horizontal" class="tabs"><li role="tab" tabindex="0" aria-selected="true" class="tabs__item tabItem_3gSF tabs__item--active" style="outline:none">Function Component</li><li role="tab" tabindex="0" aria-selected="false" class="tabs__item tabItem_3gSF" style="outline:none">Class Component</li></ul><div role="tabpanel" class="margin-vert--md"><div><div class="snack-player" data-snack-name="BackHandler" data-snack-description="Example usage" data-snack-code="import%20React%2C%20%7B%20useEffect%20%7D%20from%20%22react%22%3B%0Aimport%20%7B%20Text%2C%20View%2C%20StyleSheet%2C%20BackHandler%2C%20Alert%20%7D%20from%20%22react-native%22%3B%0A%0Aconst%20App%20%3D%20()%20%3D%3E%20%7B%0A%20%20useEffect(()%20%3D%3E%20%7B%0A%20%20%20%20const%20backAction%20%3D%20()%20%3D%3E%20%7B%0A%20%20%20%20%20%20Alert.alert(%22Hold%20on!%22%2C%20%22Are%20you%20sure%20you%20want%20to%20go%20back%3F%22%2C%20%5B%0A%20%20%20%20%20%20%20%20%7B%0A%20%20%20%20%20%20%20%20%20%20text%3A%20%22Cancel%22%2C%0A%20%20%20%20%20%20%20%20%20%20onPress%3A%20()%20%3D%3E%20null%2C%0A%20%20%20%20%20%20%20%20%20%20style%3A%20%22cancel%22%0A%20%20%20%20%20%20%20%20%7D%2C%0A%20%20%20%20%20%20%20%20%7B%20text%3A%20%22YES%22%2C%20onPress%3A%20()%20%3D%3E%20BackHandler.exitApp()%20%7D%0A%20%20%20%20%20%20%5D)%3B%0A%20%20%20%20%20%20return%20true%3B%0A%20%20%20%20%7D%3B%0A%0A%20%20%20%20const%20backHandler%20%3D%20BackHandler.addEventListener(%0A%20%20%20%20%20%20%22hardwareBackPress%22%2C%0A%20%20%20%20%20%20backAction%0A%20%20%20%20)%3B%0A%0A%20%20%20%20return%20()%20%3D%3E%20backHandler.remove()%3B%0A%20%20%7D%2C%20%5B%5D)%3B%0A%0A%20%20return%20(%0A%20%20%20%20%3CView%20style%3D%7Bstyles.container%7D%3E%0A%20%20%20%20%20%20%3CText%20style%3D%7Bstyles.text%7D%3EClick%20Back%20button!%3C%2FText%3E%0A%20%20%20%20%3C%2FView%3E%0A%20%20)%3B%0A%7D%3B%0A%0Aconst%20styles%20%3D%20StyleSheet.create(%7B%0A%20%20container%3A%20%7B%0A%20%20%20%20flex%3A%201%2C%0A%20%20%20%20alignItems%3A%20%22center%22%2C%0A%20%20%20%20justifyContent%3A%20%22center%22%0A%20%20%7D%2C%0A%20%20text%3A%20%7B%0A%20%20%20%20fontSize%3A%2018%2C%0A%20%20%20%20fontWeight%3A%20%22bold%22%0A%20%20%7D%0A%7D)%3B%0A%0Aexport%20default%20App%3B" data-snack-platform="web" data-snack-supported-platforms="android" data-snack-theme="light" data-snack-preview="true" data-snack-loading="lazy"></div></div></div></div><p><code>BackHandler.addEventListener</code> creates an event listener & returns a <code>NativeEventSubscription</code> object which should be cleared using <code>NativeEventSubscription.remove</code> method.</p><p>Additionally <code>BackHandler.removeEventListener</code> can also be used to clear the event listener. Ensure the callback has the reference to the same function used in the <code>addEventListener</code> call as shown the following example ﹣</p><div><ul role="tablist" aria-orientation="horizontal" class="tabs"><li role="tab" tabindex="0" aria-selected="true" class="tabs__item tabItem_3gSF tabs__item--active" style="outline:none">Function Component</li><li role="tab" tabindex="0" aria-selected="false" class="tabs__item tabItem_3gSF" style="outline:none">Class Component</li></ul><div role="tabpanel" class="margin-vert--md"><div><div class="snack-player" data-snack-name="BackHandler" data-snack-description="Example usage" data-snack-code="import%20React%2C%20%7B%20useEffect%20%7D%20from%20%22react%22%3B%0Aimport%20%7B%20Text%2C%20View%2C%20StyleSheet%2C%20BackHandler%2C%20Alert%20%7D%20from%20%22react-native%22%3B%0A%0Aconst%20App%20%3D%20()%20%3D%3E%20%7B%0A%20%20const%20backAction%20%3D%20()%20%3D%3E%20%7B%0A%20%20%20%20Alert.alert(%22Hold%20on!%22%2C%20%22Are%20you%20sure%20you%20want%20to%20go%20back%3F%22%2C%20%5B%0A%20%20%20%20%20%20%7B%0A%20%20%20%20%20%20%20%20text%3A%20%22Cancel%22%2C%0A%20%20%20%20%20%20%20%20onPress%3A%20()%20%3D%3E%20null%2C%0A%20%20%20%20%20%20%20%20style%3A%20%22cancel%22%0A%20%20%20%20%20%20%7D%2C%0A%20%20%20%20%20%20%7B%20text%3A%20%22YES%22%2C%20onPress%3A%20()%20%3D%3E%20BackHandler.exitApp()%20%7D%0A%20%20%20%20%5D)%3B%0A%20%20%20%20return%20true%3B%0A%20%20%7D%3B%0A%0A%20%20useEffect(()%20%3D%3E%20%7B%0A%20%20%20%20BackHandler.addEventListener(%22hardwareBackPress%22%2C%20backAction)%3B%0A%0A%20%20%20%20return%20()%20%3D%3E%0A%20%20%20%20%20%20BackHandler.removeEventListener(%22hardwareBackPress%22%2C%20backAction)%3B%0A%20%20%7D%2C%20%5B%5D)%3B%0A%0A%20%20return%20(%0A%20%20%20%20%3CView%20style%3D%7Bstyles.container%7D%3E%0A%20%20%20%20%20%20%3CText%20style%3D%7Bstyles.text%7D%3EClick%20Back%20button!%3C%2FText%3E%0A%20%20%20%20%3C%2FView%3E%0A%20%20)%3B%0A%7D%3B%0A%0Aconst%20styles%20%3D%20StyleSheet.create(%7B%0A%20%20container%3A%20%7B%0A%20%20%20%20flex%3A%201%2C%0A%20%20%20%20alignItems%3A%20%22center%22%2C%0A%20%20%20%20justifyContent%3A%20%22center%22%0A%20%20%7D%2C%0A%20%20text%3A%20%7B%0A%20%20%20%20fontSize%3A%2018%2C%0A%20%20%20%20fontWeight%3A%20%22bold%22%0A%20%20%7D%0A%7D)%3B%0A%0Aexport%20default%20App%3B" data-snack-platform="web" data-snack-supported-platforms="android" data-snack-theme="light" data-snack-preview="true" data-snack-loading="lazy"></div></div></div></div><h2><a aria-hidden="true" tabindex="-1" class="anchor enhancedAnchor_3pqN" id="usage-with-react-navigation"></a>Usage with React Navigation<a aria-hidden="true" tabindex="-1" class="hash-link" href="#usage-with-react-navigation" title="Direct link to heading">#</a></h2><p>If you are using React Navigation to navigate across different screens, you can follow their guide on <a href="https://reactnavigation.org/docs/custom-android-back-button-handling/" target="_blank" rel="noopener noreferrer">Custom Android back button behaviour</a></p><h2><a aria-hidden="true" tabindex="-1" class="anchor enhancedAnchor_3pqN" id="backhandler-hook"></a>Backhandler hook<a aria-hidden="true" tabindex="-1" class="hash-link" href="#backhandler-hook" title="Direct link to heading">#</a></h2><p><a href="https://github.com/react-native-community/hooks#usebackhandler" target="_blank" rel="noopener noreferrer">React Native Hooks</a> has a nice <code>useBackHandler</code> hook which will simplify the process of setting up event listeners.</p><hr><h1><a aria-hidden="true" tabindex="-1" class="anchor enhancedAnchor_3pqN" id="reference"></a>Reference<a aria-hidden="true" tabindex="-1" class="hash-link" href="#reference" title="Direct link to heading">#</a></h1><h2><a aria-hidden="true" tabindex="-1" class="anchor enhancedAnchor_3pqN" id="methods"></a>Methods<a aria-hidden="true" tabindex="-1" class="hash-link" href="#methods" title="Direct link to heading">#</a></h2><h3><a aria-hidden="true" tabindex="-1" class="anchor enhancedAnchor_3pqN" id="addeventlistener"></a><code>addEventListener()</code><a aria-hidden="true" tabindex="-1" class="hash-link" href="#addeventlistener" title="Direct link to heading">#</a></h3><div class="mdxCodeBlock_xYIz"><div class="codeBlockContent_rlEb"><button tabindex="0" type="button" aria-label="Copy code to clipboard" class="copyButton_kOW4">Copy</button><div class="prism-code language-jsx codeBlock_1AP7"><div class="codeBlockLines_1boI" style="color:#FFFFFF;background:#282C34"><div class="token-line" style="color:#FFFFFF;background:#282C34"><span class="token keyword" style="color:#c5a5c5">static</span><span class="token plain"> </span><span class="token function" style="color:#79b6f2">addEventListener</span><span class="token punctuation" style="color:#657b83">(</span><span class="token plain">eventName</span><span class="token punctuation" style="color:#657b83">,</span><span class="token plain"> handler</span><span class="token punctuation" style="color:#657b83">)</span></div></div></div></div></div><hr><h3><a aria-hidden="true" tabindex="-1" class="anchor enhancedAnchor_3pqN" id="exitapp"></a><code>exitApp()</code><a aria-hidden="true" tabindex="-1" class="hash-link" href="#exitapp" title="Direct link to heading">#</a></h3><div class="mdxCodeBlock_xYIz"><div class="codeBlockContent_rlEb"><button tabindex="0" type="button" aria-label="Copy code to clipboard" class="copyButton_kOW4">Copy</button><div class="prism-code language-jsx codeBlock_1AP7"><div class="codeBlockLines_1boI" style="color:#FFFFFF;background:#282C34"><div class="token-line" style="color:#FFFFFF;background:#282C34"><span class="token keyword" style="color:#c5a5c5">static</span><span class="token plain"> </span><span class="token function" style="color:#79b6f2">exitApp</span><span class="token punctuation" style="color:#657b83">(</span><span class="token punctuation" style="color:#657b83">)</span></div></div></div></div></div><hr><h3><a aria-hidden="true" tabindex="-1" class="anchor enhancedAnchor_3pqN" id="removeeventlistener"></a><code>removeEventListener()</code><a aria-hidden="true" tabindex="-1" class="hash-link" href="#removeeventlistener" title="Direct link to heading">#</a></h3><div class="mdxCodeBlock_xYIz"><div class="codeBlockContent_rlEb"><button tabindex="0" type="button" aria-label="Copy code to clipboard" class="copyButton_kOW4">Copy</button><div class="prism-code language-jsx codeBlock_1AP7"><div class="codeBlockLines_1boI" style="color:#FFFFFF;background:#282C34"><div class="token-line" style="color:#FFFFFF;background:#282C34"><span class="token keyword" style="color:#c5a5c5">static</span><span class="token plain"> </span><span class="token function" style="color:#79b6f2">removeEventListener</span><span class="token punctuation" style="color:#657b83">(</span><span class="token plain">eventName</span><span class="token punctuation" style="color:#657b83">,</span><span class="token plain"> handler</span><span class="token punctuation" style="color:#657b83">)</span></div></div></div></div></div></div></article><div class="docMetadata margin-vert--xl"><div class="row"><div class="col"><a href="https://github.com/facebook/react-native-website/blob/master/website/../docs/backhandler.md" target="_blank" rel="noreferrer noopener"><svg fill="currentColor" height="1.2em" width="1.2em" preserveAspectRatio="xMidYMid meet" viewBox="0 0 40 40" style="margin-right:0.3em;vertical-align:sub"><g><path d="m34.5 11.7l-3 3.1-6.3-6.3 3.1-3q0.5-0.5 1.2-0.5t1.1 0.5l3.9 3.9q0.5 0.4 0.5 1.1t-0.5 1.2z m-29.5 17.1l18.4-18.5 6.3 6.3-18.4 18.4h-6.3v-6.2z"></path></g></svg>Edit this page</a></div><div class="col text--right"><em><small class="docMetadata-updated">Last updated on <time datetime="2020-12-07T11:00:02.000Z" class="docLastUpdatedAt_1gIo">12/7/2020</time></small></em></div></div></div><div class="margin-vert--lg"><nav class="pagination-nav" aria-label="Blog list page navigation"><div class="pagination-nav__item"><a class="pagination-nav__link" href="/docs/next/usewindowdimensions"><div class="pagination-nav__sublabel">Previous</div><div class="pagination-nav__label">« useWindowDimensions</div></a></div><div class="pagination-nav__item pagination-nav__item--next"><a class="pagination-nav__link" href="/docs/next/permissionsandroid"><div class="pagination-nav__sublabel">Next</div><div class="pagination-nav__label">PermissionsAndroid »</div></a></div></nav></div></div></div><div class="col col--3"><div class="tableOfContents_3iuQ"><ul class="table-of-contents table-of-contents__left-border"><li><a href="#pattern" class="table-of-contents__link">Pattern</a></li><li><a href="#example" class="table-of-contents__link">Example</a></li><li><a href="#usage-with-react-navigation" class="table-of-contents__link">Usage with React Navigation</a></li><li><a href="#backhandler-hook" class="table-of-contents__link">Backhandler hook</a></li><li><a href="#methods" class="table-of-contents__link">Methods</a><ul><li><a href="#addeventlistener" class="table-of-contents__link"><code>addEventListener()</code></a></li><li><a href="#exitapp" class="table-of-contents__link"><code>exitApp()</code></a></li><li><a href="#removeeventlistener" class="table-of-contents__link"><code>removeEventListener()</code></a></li></ul></li></ul></div></div></div></div></main></div></div><footer class="footer footer--dark"><div class="container"><div class="row footer__links"><div class="col footer__col"><h4 class="footer__title">Docs</h4><ul class="footer__items"><li class="footer__item"><a class="footer__link-item" href="/docs/getting-started">Getting Started</a></li><li class="footer__item"><a class="footer__link-item" href="/docs/tutorial">Tutorial</a></li><li class="footer__item"><a class="footer__link-item" href="/docs/components-and-apis">Components and APIs</a></li><li class="footer__item"><a class="footer__link-item" href="/docs/more-resources">More Resources</a></li></ul></div><div class="col footer__col"><h4 class="footer__title">Community</h4><ul class="footer__items"><li class="footer__item"><a class="footer__link-item" href="/help">The React Native Community</a></li><li class="footer__item"><a class="footer__link-item" 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