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Содержание
  1. Разработка приложений Android с помощью React Native
  2. Обзор
  3. Начало работы с React Native путем установки требуемых средств
  4. Создание нового проекта с помощью React Native
  5. Setting up the development environment
  6. Running your React Native application
  7. Modifying your app
  8. That’s it!
  9. Now what?
  10. Running your app on a simulator or virtual device
  11. Caveats
  12. Development OS​
  13. Target OS​
  14. Installing dependencies​
  15. Node & Watchman
  16. Java Development Kit
  17. Android development environment
  18. 1. Install Android Studio
  19. 2. Install the Android SDK
  20. 3. Configure the ANDROID_HOME environment variable
  21. React Native Command Line Interface
  22. Creating a new application
  23. [Optional] Using a specific version or template
  24. Preparing the Android device
  25. Using a physical device
  26. Using a virtual device
  27. Running your React Native application
  28. Step 1: Start Metro
  29. Step 2: Start your application
  30. Modifying your app
  31. That’s it!
  32. Now what?
  33. Installing dependencies​
  34. Node & Watchman​
  35. Xcode​
  36. Command Line Tools​
  37. Installing an iOS Simulator in Xcode​
  38. CocoaPods​
  39. React Native Command Line Interface​
  40. Creating a new application​
  41. [Optional] Using a specific version or template​
  42. Running your React Native application​
  43. Step 1: Start Metro​
  44. Step 2: Start your application​
  45. Running on a device​
  46. Modifying your app​
  47. That’s it!​
  48. Now what?​
  49. Target OS​
  50. Installing dependencies
  51. Node, JDK
  52. Android development environment
  53. 1. Install Android Studio
  54. 2. Install the Android SDK
  55. 3. Configure the ANDROID_HOME environment variable
  56. 4. Add platform-tools to Path
  57. React Native Command Line Interface
  58. Creating a new application
  59. [Optional] Using a specific version or template
  60. Preparing the Android device
  61. Using a physical device
  62. Using a virtual device
  63. Running your React Native application
  64. Step 1: Start Metro
  65. Step 2: Start your application
  66. Modifying your app
  67. That’s it!
  68. Now what?
  69. Unsupported​
  70. Target OS​
  71. Installing dependencies​
  72. Java Development Kit
  73. Android development environment
  74. 1. Install Android Studio
  75. 2. Install the Android SDK
  76. 3. Configure the ANDROID_HOME environment variable
  77. Watchman
  78. React Native Command Line Interface
  79. Creating a new application
  80. [Optional] Using a specific version or template
  81. Preparing the Android device
  82. Using a physical device
  83. Using a virtual device
  84. Running your React Native application
  85. Step 1: Start Metro
  86. Step 2: Start your application
  87. Modifying your app
  88. That’s it!
  89. Now what?
  90. Unsupported​

Разработка приложений Android с помощью React Native

Это руководство поможет вам начать работу с React Native в Windows для создания кросс-платформенных приложений, которые будут работать на устройствах Android.

Обзор

React Native — это платформа для разработки мобильных приложений с открытым кодом, созданная Facebook. Она используется для разработки приложений для Android, iOS, Интернета и UWP (Windows). Решение предоставляет собственные элементы управления пользовательского интерфейса и полный доступ к собственной платформе. Для работы с React Native требуется понимание основ JavaScript.

Начало работы с React Native путем установки требуемых средств

Установите Android Studio для Windows. По умолчанию Android Studio устанавливает последнюю версию пакета SDK для Android. Для работы с React Native требуется пакет SDK для Android 6.0 (Marshmallow) или более поздней версии. Мы рекомендуем использовать последнюю версию пакета SDK.

Создайте пути к переменным среды для пакетов SDK для Java и Android:

  • В меню поиска Windows введите: «изменить системные переменные среды». Откроется окно Свойства системы.
  • Выберите элемент Переменные среды и нажмите кнопку Создать в разделе Пользовательские переменные.
  • Введите имя и значение переменной (путь). Ниже приведены пути по умолчанию для пакетов SDK для Java и Android. Если вы выбрали определенное расположение для установки пакетов SDK для Java и Android, обязательно обновите пути к переменной соответствующим образом.
    • JAVA_HOME: C:\Program Files\Android\Android Studio\jre\jre
    • ANDROID_HOME: C:\Users\имя_пользователя\AppData\Local\Android\Sdk

Установите Node.js для Windows. Вы можете использовать nvm для Windows, если работаете с несколькими проектами и версиями Node.js. Мы рекомендуем установить последнюю версию LTS для новых проектов.

Кроме того, вы можете установить и использовать Терминал Windows для работы с удобным для вас интерфейсом командной строки (CLI), а также Git для управления версиями. Java JDK поставляется с Android Studio версии 2.2 и выше, но, если вам нужно обновить JDK отдельно от Android Studio, используйте установщик Windows x64.

Создание нового проекта с помощью React Native

Используйте npx, средство запуска пакетов, которое устанавливается вместе с npm, чтобы создать новый проект React Native из командной строки Windows, PowerShell, Терминал Windowsили интегрированного терминала в VS Code (просмотр интегрированного терминала).

Откройте новый каталог MyReactNativeApp:

Чтобы запустить проект на физическом устройстве с Android, подключите устройство к компьютеру с помощью USB-кабеля.

Чтобы запустить проект в эмуляторе Android, не нужно выполнять никаких действий, так как Android Studio поставляется с установленным эмулятором по умолчанию. Чтобы запустить приложение в эмуляторе для определенного устройства, нажмите кнопку AVD Manager (Диспетчер AVD) на панели инструментов.

.

Чтобы запустить проект, выполните указанную ниже команду. Откроется новое окно консоли, в котором отобразится средство увязки в пакеты Metro в Node.

Если вы используете новую установку Android Studio и еще не разрабатывали приложения Android, при запуске приложения на этапе принятия лицензий для пакета SDK для Android в командной строке могут возникнуть ошибки. Например «предупреждение: лицензия для пакета пакет SDK для Android Платформа 29 не принята». Чтобы устранить эту проблему, можно нажать кнопку Диспетчер пакетов SDK в Android Studio . Кроме того, вы можете перечислить и принять лицензии с помощью следующей команды, используя путь к расположению пакета SDK на компьютере.

Чтобы изменить приложение, откройте каталог проекта MyReactNativeApp в удобной для вас среде IDE. Мы рекомендуем использовать VS Code или Android Studio.

В шаблоне проекта, созданном с помощью react-native init , используется главная страница с именем App.js . На этой странице предоставляются полезные ссылки на материалы о разработке с помощью React Native. Добавьте некоторый текст в первый текстовый элемент, например строку «Hello World!», показанную ниже.

Перезагрузите приложение, чтобы отобразились внесенные изменения. Для этого существует несколько способов.

  • В окне консоли средства увязки в пакеты Metro введите r.
  • В эмуляторе устройства Android дважды коснитесь r на клавиатуре.
  • Дважды встряхните физическое устройство Android, чтобы открыть меню отладки React Native, и выберите команду Reload (Перезагрузить).

Источник

Setting up the development environment

This page will help you install and build your first React Native app.

If you are new to mobile development, the easiest way to get started is with Expo CLI. Expo is a set of tools built around React Native and, while it has many features, the most relevant feature for us right now is that it can get you writing a React Native app within minutes. You will only need a recent version of Node.js and a phone or emulator. If you’d like to try out React Native directly in your web browser before installing any tools, you can try out Snack.

If you are already familiar with mobile development, you may want to use React Native CLI. It requires Xcode or Android Studio to get started. If you already have one of these tools installed, you should be able to get up and running within a few minutes. If they are not installed, you should expect to spend about an hour installing and configuring them.

  • Expo CLI Quickstart
  • React Native CLI Quickstart

Assuming that you have Node 12 LTS or greater installed, you can use npm to install the Expo CLI command line utility:

Then run the following commands to create a new React Native project called «AwesomeProject»:

This will start a development server for you.

Running your React Native application

Install the Expo client app on your iOS or Android phone and connect to the same wireless network as your computer. On Android, use the Expo app to scan the QR code from your terminal to open your project. On iOS, use the built-in QR code scanner of the Camera app.

Modifying your app

Now that you have successfully run the app, let’s modify it. Open App.js in your text editor of choice and edit some lines. The application should reload automatically once you save your changes.

That’s it!

Congratulations! You’ve successfully run and modified your first React Native app.

Now what?

Expo also has docs you can reference if you have questions specific to the tool. You can also ask for help at Expo forums.

These tools help you get started quickly, but before committing to building your app with Expo CLI, read about the limitations.

If you have a problem with Expo, before creating a new issue, please see if there’s an existing issue about it:

  • in the Expo CLI issues (for issues related to Expo CLI), or
  • in the Expo issues (for issues about the Expo client or SDK).

If you’re curious to learn more about React Native, check out the Introduction to React Native.

Running your app on a simulator or virtual device

Expo CLI allows you to run your React Native app on a physical device without setting up a development environment. If you want to run your app on the iOS Simulator or an Android Virtual Device, please refer to the instructions for «React Native CLI Quickstart» to learn how to install Xcode or set up your Android development environment.

Once you’ve set these up, you can launch your app on an Android Virtual Device by running npm run android , or on the iOS Simulator by running npm run ios (macOS only).

Caveats

Because you don’t build any native code when using Expo to create a project, it’s not possible to include custom native modules beyond the React Native APIs and components that are available in the Expo client app.

If you know that you’ll eventually need to include your own native code, Expo is still a good way to get started. In that case you’ll need to «eject» eventually to create your own native builds. If you do eject, the «React Native CLI Quickstart» instructions will be required to continue working on your project.

Expo CLI configures your project to use the most recent React Native version that is supported by the Expo client app. The Expo client app usually gains support for a given React Native version about a week after the React Native version is released as stable. You can check this document to find out what versions are supported.

If you’re integrating React Native into an existing project, you’ll want to skip Expo CLI and go directly to setting up the native build environment. Select «React Native CLI Quickstart» above for instructions on configuring a native build environment for React Native.

Follow these instructions if you need to build native code in your project. For example, if you are integrating React Native into an existing application, or if you «ejected» from Expo, you’ll need this section.

The instructions are a bit different depending on your development operating system, and whether you want to start developing for iOS or Android. If you want to develop for both Android and iOS, that’s fine — you can pick one to start with, since the setup is a bit different.

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Development OS​

Target OS​

Installing dependencies​

You will need Node, Watchman, the React Native command line interface, a JDK, and Android Studio.

While you can use any editor of your choice to develop your app, you will need to install Android Studio in order to set up the necessary tooling to build your React Native app for Android.

Node & Watchman

We recommend installing Node and Watchman using Homebrew. Run the following commands in a Terminal after installing Homebrew:

If you have already installed Node on your system, make sure it is Node 12 or newer.

Watchman is a tool by Facebook for watching changes in the filesystem. It is highly recommended you install it for better performance.

Java Development Kit

We recommend installing JDK using Homebrew. Run the following commands in a Terminal after installing Homebrew:

If you have already installed JDK on your system, make sure it is JDK 8 or newer.

Android development environment

Setting up your development environment can be somewhat tedious if you’re new to Android development. If you’re already familiar with Android development, there are a few things you may need to configure. In either case, please make sure to carefully follow the next few steps.

1. Install Android Studio

Download and install Android Studio. While on Android Studio installation wizard, make sure the boxes next to all of the following items are checked:

  • Android SDK
  • Android SDK Platform
  • Android Virtual Device

Then, click «Next» to install all of these components.

If the checkboxes are grayed out, you will have a chance to install these components later on.

Once setup has finalized and you’re presented with the Welcome screen, proceed to the next step.

2. Install the Android SDK

Android Studio installs the latest Android SDK by default. Building a React Native app with native code, however, requires the Android 10 (Q) SDK in particular. Additional Android SDKs can be installed through the SDK Manager in Android Studio.

To do that, open Android Studio, click on «Configure» button and select «SDK Manager».

The SDK Manager can also be found within the Android Studio «Preferences» dialog, under Appearance & Behavior → System Settings → Android SDK.

Select the «SDK Platforms» tab from within the SDK Manager, then check the box next to «Show Package Details» in the bottom right corner. Look for and expand the Android 10 (Q) entry, then make sure the following items are checked:

  • Android SDK Platform 29
  • Intel x86 Atom_64 System Image or Google APIs Intel x86 Atom System Image

Next, select the «SDK Tools» tab and check the box next to «Show Package Details» here as well. Look for and expand the «Android SDK Build-Tools» entry, then make sure that 29.0.2 is selected and check the «Android SDK Command-line Tools (latest)».

Finally, click «Apply» to download and install the Android SDK and related build tools.

You can also run the following command after setting ANDROID_HOME.

3. Configure the ANDROID_HOME environment variable

The React Native tools require some environment variables to be set up in order to build apps with native code.

Add the following lines to your $HOME/.bash_profile or $HOME/.bashrc (if you are using zsh then

/.zshrc ) config file:

.bash_profile is specific to bash . If you’re using another shell, you will need to edit the appropriate shell-specific config file.

Type source $HOME/.bash_profile for bash or source $HOME/.zprofile to load the config into your current shell. Verify that ANDROID_HOME has been set by running echo $ANDROID_HOME and the appropriate directories have been added to your path by running echo $PATH .

Please make sure you use the correct Android SDK path. You can find the actual location of the SDK in the Android Studio «Preferences» dialog, under Appearance & Behavior → System Settings → Android SDK.

React Native Command Line Interface

React Native has a built-in command line interface. Rather than install and manage a specific version of the CLI globally, we recommend you access the current version at runtime using npx , which ships with Node.js. With npx react-native , the current stable version of the CLI will be downloaded and executed at the time the command is run.

Creating a new application

If you previously installed a global react-native-cli package, please remove it as it may cause unexpected issues.

React Native has a built-in command line interface, which you can use to generate a new project. You can access it without installing anything globally using npx , which ships with Node.js. Let’s create a new React Native project called «AwesomeProject»:

This is not necessary if you are integrating React Native into an existing application, if you «ejected» from Expo, or if you’re adding Android support to an existing React Native project (see Integration with Existing Apps). You can also use a third-party CLI to init your React Native app, such as Ignite CLI.

[Optional] Using a specific version or template

If you want to start a new project with a specific React Native version, you can use the —version argument:

You can also start a project with a custom React Native template, like TypeScript, with —template argument:

Preparing the Android device

You will need an Android device to run your React Native Android app. This can be either a physical Android device, or more commonly, you can use an Android Virtual Device which allows you to emulate an Android device on your computer.

Either way, you will need to prepare the device to run Android apps for development.

Using a physical device

If you have a physical Android device, you can use it for development in place of an AVD by plugging it in to your computer using a USB cable and following the instructions here.

Using a virtual device

If you use Android Studio to open ./AwesomeProject/android , you can see the list of available Android Virtual Devices (AVDs) by opening the «AVD Manager» from within Android Studio. Look for an icon that looks like this:

If you have recently installed Android Studio, you will likely need to create a new AVD. Select «Create Virtual Device. «, then pick any Phone from the list and click «Next», then select the Q API Level 29 image.

Click «Next» then «Finish» to create your AVD. At this point you should be able to click on the green triangle button next to your AVD to launch it, then proceed to the next step.

Running your React Native application

Step 1: Start Metro

First, you will need to start Metro, the JavaScript bundler that ships with React Native. Metro «takes in an entry file and various options, and returns a single JavaScript file that includes all your code and its dependencies.»—Metro Docs

To start Metro, run npx react-native start inside your React Native project folder:

react-native start starts Metro Bundler.

If you use the Yarn package manager, you can use yarn instead of npx when running React Native commands inside an existing project.

If you’re familiar with web development, Metro is a lot like webpack—for React Native apps. Unlike Kotlin or Java, JavaScript isn’t compiled—and neither is React Native. Bundling isn’t the same as compiling, but it can help improve startup performance and translate some platform-specific JavaScript into more widely supported JavaScript.

Step 2: Start your application

Let Metro Bundler run in its own terminal. Open a new terminal inside your React Native project folder. Run the following:

If everything is set up correctly, you should see your new app running in your Android emulator shortly.

npx react-native run-android is one way to run your app — you can also run it directly from within Android Studio.

If you can’t get this to work, see the Troubleshooting page.

Modifying your app

Now that you have successfully run the app, let’s modify it.

  • Open App.js in your text editor of choice and edit some lines.
  • Press the R key twice or select Reload from the Developer Menu ( ⌘M ) to see your changes!

That’s it!

Congratulations! You’ve successfully run and modified your first React Native app.

Now what?

  • If you want to add this new React Native code to an existing application, check out the Integration guide.

If you’re curious to learn more about React Native, check out the Introduction to React Native.

Installing dependencies​

You will need Node, Watchman, the React Native command line interface, Xcode and CocoaPods.

While you can use any editor of your choice to develop your app, you will need to install Xcode in order to set up the necessary tooling to build your React Native app for iOS.

Node & Watchman​

We recommend installing Node and Watchman using Homebrew. Run the following commands in a Terminal after installing Homebrew:

If you have already installed Node on your system, make sure it is Node 12 or newer.

Watchman is a tool by Facebook for watching changes in the filesystem. It is highly recommended you install it for better performance.

Xcode​

The easiest way to install Xcode is via the Mac App Store. Installing Xcode will also install the iOS Simulator and all the necessary tools to build your iOS app.

If you have already installed Xcode on your system, make sure it is version 10 or newer.

Command Line Tools​

You will also need to install the Xcode Command Line Tools. Open Xcode, then choose «Preferences. » from the Xcode menu. Go to the Locations panel and install the tools by selecting the most recent version in the Command Line Tools dropdown.

Installing an iOS Simulator in Xcode​

To install a simulator, open Xcode > Preferences. and select the Components tab. Select a simulator with the corresponding version of iOS you wish to use.

CocoaPods​

CocoaPods is built with Ruby and it will be installable with the default Ruby available on macOS. You can use a Ruby Version manager, however we recommend that you use the standard Ruby available on macOS unless you know what you’re doing.

Using the default Ruby install will require you to use sudo when installing gems. (This is only an issue for the duration of the gem installation, though.)

For more information, please visit CocoaPods Getting Started guide.

React Native Command Line Interface​

React Native has a built-in command line interface. Rather than install and manage a specific version of the CLI globally, we recommend you access the current version at runtime using npx , which ships with Node.js. With npx react-native , the current stable version of the CLI will be downloaded and executed at the time the command is run.

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Creating a new application​

If you previously installed a global react-native-cli package, please remove it as it may cause unexpected issues.

You can use React Native’s built-in command line interface to generate a new project. Let’s create a new React Native project called «AwesomeProject»:

This is not necessary if you are integrating React Native into an existing application, if you «ejected» from Expo, or if you’re adding iOS support to an existing React Native project (see Integration with Existing Apps). You can also use a third-party CLI to init your React Native app, such as Ignite CLI.

[Optional] Using a specific version or template​

If you want to start a new project with a specific React Native version, you can use the —version argument:

You can also start a project with a custom React Native template, like TypeScript, with —template argument:

Note If the above command is failing, you may have old version of react-native or react-native-cli installed globally on your pc. Try uninstalling the cli and run the cli using npx .

Running your React Native application​

Step 1: Start Metro​

First, you will need to start Metro, the JavaScript bundler that ships with React Native. Metro «takes in an entry file and various options, and returns a single JavaScript file that includes all your code and its dependencies.»—Metro Docs

To start Metro, run npx react-native start inside your React Native project folder:

react-native start starts Metro Bundler.

If you use the Yarn package manager, you can use yarn instead of npx when running React Native commands inside an existing project.

If you’re familiar with web development, Metro is a lot like webpack—for React Native apps. Unlike Kotlin or Java, JavaScript isn’t compiled—and neither is React Native. Bundling isn’t the same as compiling, but it can help improve startup performance and translate some platform-specific JavaScript into more widely supported JavaScript.

Step 2: Start your application​

Let Metro Bundler run in its own terminal. Open a new terminal inside your React Native project folder. Run the following:

You should see your new app running in the iOS Simulator shortly.

npx react-native run-ios is one way to run your app. You can also run it directly from within Xcode.

If you can’t get this to work, see the Troubleshooting page.

Running on a device​

The above command will automatically run your app on the iOS Simulator by default. If you want to run the app on an actual physical iOS device, please follow the instructions here.

Modifying your app​

Now that you have successfully run the app, let’s modify it.

  • Open App.js in your text editor of choice and edit some lines.
  • Hit ⌘R in your iOS Simulator to reload the app and see your changes!

That’s it!​

Congratulations! You’ve successfully run and modified your first React Native app.

Now what?​

  • If you want to add this new React Native code to an existing application, check out the Integration guide.

If you’re curious to learn more about React Native, check out the Introduction to React Native.

Target OS​

Installing dependencies

You will need Node, the React Native command line interface, a JDK, and Android Studio.

While you can use any editor of your choice to develop your app, you will need to install Android Studio in order to set up the necessary tooling to build your React Native app for Android.

Node, JDK

We recommend installing Node via Chocolatey, a popular package manager for Windows.

If you want to be able to switch between different Node versions, you might want to install Node via nvm-windows, a Node version manager for Windows.

React Native also requires Java SE Development Kit (JDK), which can be installed using Chocolatey as well.

Open an Administrator Command Prompt (right click Command Prompt and select «Run as Administrator»), then run the following command:

If you have already installed Node on your system, make sure it is Node 12 or newer. If you already have a JDK on your system, make sure it is version 8 or newer.

You can find additional installation options on Node’s Downloads page.

If you’re using the latest version of Java Development Kit, you’ll need to change the Gradle version of your project so it can recognize the JDK. You can do that by going to \android\gradle\wrapper\gradle-wrapper.properties and changing the distributionUrl value to upgrade the Gradle version. You can check out here the lastest releases of Gradle.

Android development environment

Setting up your development environment can be somewhat tedious if you’re new to Android development. If you’re already familiar with Android development, there are a few things you may need to configure. In either case, please make sure to carefully follow the next few steps.

1. Install Android Studio

Download and install Android Studio. While on Android Studio installation wizard, make sure the boxes next to all of the following items are checked:

  • Android SDK
  • Android SDK Platform
  • Android Virtual Device
  • If you are not already using Hyper-V: Performance (Intel ® HAXM) (See here for AMD or Hyper-V)

Then, click «Next» to install all of these components.

If the checkboxes are grayed out, you will have a chance to install these components later on.

Once setup has finalized and you’re presented with the Welcome screen, proceed to the next step.

2. Install the Android SDK

Android Studio installs the latest Android SDK by default. Building a React Native app with native code, however, requires the Android 10 (Q) SDK in particular. Additional Android SDKs can be installed through the SDK Manager in Android Studio.

To do that, open Android Studio, click on «Configure» button and select «SDK Manager».

The SDK Manager can also be found within the Android Studio «Preferences» dialog, under Appearance & Behavior → System Settings → Android SDK.

Select the «SDK Platforms» tab from within the SDK Manager, then check the box next to «Show Package Details» in the bottom right corner. Look for and expand the Android 10 (Q) entry, then make sure the following items are checked:

  • Android SDK Platform 29
  • Intel x86 Atom_64 System Image or Google APIs Intel x86 Atom System Image

Next, select the «SDK Tools» tab and check the box next to «Show Package Details» here as well. Look for and expand the «Android SDK Build-Tools» entry, then make sure that 29.0.2 is selected.

Finally, click «Apply» to download and install the Android SDK and related build tools.

3. Configure the ANDROID_HOME environment variable

The React Native tools require some environment variables to be set up in order to build apps with native code.

  1. Open the Windows Control Panel.
  2. Click on User Accounts, then click User Accounts again
  3. Click on Change my environment variables
  4. Click on New. to create a new ANDROID_HOME user variable that points to the path to your Android SDK:

The SDK is installed, by default, at the following location:

You can find the actual location of the SDK in the Android Studio «Settings» dialog, under Appearance & Behavior → System Settings → Android SDK.

Open a new Command Prompt window to ensure the new environment variable is loaded before proceeding to the next step.

  1. Open powershell
  2. Copy and paste Get-ChildItem -Path Env: \ into powershell
  3. Verify ANDROID_HOME has been added

4. Add platform-tools to Path

  1. Open the Windows Control Panel.
  2. Click on User Accounts, then click User Accounts again
  3. Click on Change my environment variables
  4. Select the Path variable.
  5. Click Edit.
  6. Click New and add the path to platform-tools to the list.

The default location for this folder is:

React Native Command Line Interface

React Native has a built-in command line interface. Rather than install and manage a specific version of the CLI globally, we recommend you access the current version at runtime using npx , which ships with Node.js. With npx react-native , the current stable version of the CLI will be downloaded and executed at the time the command is run.

Creating a new application

If you previously installed a global react-native-cli package, please remove it as it may cause unexpected issues.

React Native has a built-in command line interface, which you can use to generate a new project. You can access it without installing anything globally using npx , which ships with Node.js. Let’s create a new React Native project called «AwesomeProject»:

This is not necessary if you are integrating React Native into an existing application, if you «ejected» from Expo, or if you’re adding Android support to an existing React Native project (see Integration with Existing Apps). You can also use a third-party CLI to init your React Native app, such as Ignite CLI.

[Optional] Using a specific version or template

If you want to start a new project with a specific React Native version, you can use the —version argument:

You can also start a project with a custom React Native template, like TypeScript, with —template argument:

Preparing the Android device

You will need an Android device to run your React Native Android app. This can be either a physical Android device, or more commonly, you can use an Android Virtual Device which allows you to emulate an Android device on your computer.

Either way, you will need to prepare the device to run Android apps for development.

Using a physical device

If you have a physical Android device, you can use it for development in place of an AVD by plugging it in to your computer using a USB cable and following the instructions here.

Using a virtual device

If you use Android Studio to open ./AwesomeProject/android , you can see the list of available Android Virtual Devices (AVDs) by opening the «AVD Manager» from within Android Studio. Look for an icon that looks like this:

If you have recently installed Android Studio, you will likely need to create a new AVD. Select «Create Virtual Device. «, then pick any Phone from the list and click «Next», then select the Q API Level 29 image.

If you don’t have HAXM installed, click on «Install HAXM» or follow these instructions to set it up, then go back to the AVD Manager.

Click «Next» then «Finish» to create your AVD. At this point you should be able to click on the green triangle button next to your AVD to launch it, then proceed to the next step.

Running your React Native application

Step 1: Start Metro

First, you will need to start Metro, the JavaScript bundler that ships with React Native. Metro «takes in an entry file and various options, and returns a single JavaScript file that includes all your code and its dependencies.»—Metro Docs

To start Metro, run npx react-native start inside your React Native project folder:

react-native start starts Metro Bundler.

If you use the Yarn package manager, you can use yarn instead of npx when running React Native commands inside an existing project.

If you’re familiar with web development, Metro is a lot like webpack—for React Native apps. Unlike Kotlin or Java, JavaScript isn’t compiled—and neither is React Native. Bundling isn’t the same as compiling, but it can help improve startup performance and translate some platform-specific JavaScript into more widely supported JavaScript.

Step 2: Start your application

Let Metro Bundler run in its own terminal. Open a new terminal inside your React Native project folder. Run the following:

If everything is set up correctly, you should see your new app running in your Android emulator shortly.

npx react-native run-android is one way to run your app — you can also run it directly from within Android Studio.

If you can’t get this to work, see the Troubleshooting page.

Modifying your app

Now that you have successfully run the app, let’s modify it.

  • Open App.js in your text editor of choice and edit some lines.
  • Press the R key twice or select Reload from the Developer Menu ( Ctrl + M ) to see your changes!

That’s it!

Congratulations! You’ve successfully run and modified your first React Native app.

Now what?

  • If you want to add this new React Native code to an existing application, check out the Integration guide.

If you’re curious to learn more about React Native, check out the Introduction to React Native.

Unsupported​

A Mac is required to build projects with native code for iOS. You can follow the Expo CLI Quickstart to learn how to build your app using Expo instead.

Target OS​

Installing dependencies​

You will need Node, the React Native command line interface, a JDK, and Android Studio.

While you can use any editor of your choice to develop your app, you will need to install Android Studio in order to set up the necessary tooling to build your React Native app for Android.

Java Development Kit

React Native requires at least the version 8 of the Java SE Development Kit (JDK). You may download and install OpenJDK from AdoptOpenJDK or your system packager. You may also Download and install Oracle JDK 14 if desired.

Android development environment

Setting up your development environment can be somewhat tedious if you’re new to Android development. If you’re already familiar with Android development, there are a few things you may need to configure. In either case, please make sure to carefully follow the next few steps.

1. Install Android Studio

Download and install Android Studio. While on Android Studio installation wizard, make sure the boxes next to all of the following items are checked:

  • Android SDK
  • Android SDK Platform
  • Android Virtual Device

Then, click «Next» to install all of these components.

If the checkboxes are grayed out, you will have a chance to install these components later on.

Once setup has finalized and you’re presented with the Welcome screen, proceed to the next step.

2. Install the Android SDK

Android Studio installs the latest Android SDK by default. Building a React Native app with native code, however, requires the Android 10 (Q) SDK in particular. Additional Android SDKs can be installed through the SDK Manager in Android Studio.

To do that, open Android Studio, click on «Configure» button and select «SDK Manager».

The SDK Manager can also be found within the Android Studio «Preferences» dialog, under Appearance & Behavior → System Settings → Android SDK.

Select the «SDK Platforms» tab from within the SDK Manager, then check the box next to «Show Package Details» in the bottom right corner. Look for and expand the Android 10 (Q) entry, then make sure the following items are checked:

  • Android SDK Platform 29
  • Intel x86 Atom_64 System Image or Google APIs Intel x86 Atom System Image

Next, select the «SDK Tools» tab and check the box next to «Show Package Details» here as well. Look for and expand the «Android SDK Build-Tools» entry, then make sure that 29.0.2 is selected.

Finally, click «Apply» to download and install the Android SDK and related build tools.

3. Configure the ANDROID_HOME environment variable

The React Native tools require some environment variables to be set up in order to build apps with native code.

Add the following lines to your $HOME/.bash_profile or $HOME/.bashrc (if you are using zsh then

/.zshrc ) config file:

.bash_profile is specific to bash . If you’re using another shell, you will need to edit the appropriate shell-specific config file.

Type source $HOME/.bash_profile for bash or source $HOME/.zprofile to load the config into your current shell. Verify that ANDROID_HOME has been set by running echo $ANDROID_HOME and the appropriate directories have been added to your path by running echo $PATH .

Please make sure you use the correct Android SDK path. You can find the actual location of the SDK in the Android Studio «Preferences» dialog, under Appearance & Behavior → System Settings → Android SDK.

Watchman

Follow the Watchman installation guide to compile and install Watchman from source.

Watchman is a tool by Facebook for watching changes in the filesystem. It is highly recommended you install it for better performance and increased compatibility in certain edge cases (translation: you may be able to get by without installing this, but your mileage may vary; installing this now may save you from a headache later).

React Native Command Line Interface

React Native has a built-in command line interface. Rather than install and manage a specific version of the CLI globally, we recommend you access the current version at runtime using npx , which ships with Node.js. With npx react-native , the current stable version of the CLI will be downloaded and executed at the time the command is run.

Creating a new application

If you previously installed a global react-native-cli package, please remove it as it may cause unexpected issues.

React Native has a built-in command line interface, which you can use to generate a new project. You can access it without installing anything globally using npx , which ships with Node.js. Let’s create a new React Native project called «AwesomeProject»:

This is not necessary if you are integrating React Native into an existing application, if you «ejected» from Expo, or if you’re adding Android support to an existing React Native project (see Integration with Existing Apps). You can also use a third-party CLI to init your React Native app, such as Ignite CLI.

[Optional] Using a specific version or template

If you want to start a new project with a specific React Native version, you can use the —version argument:

You can also start a project with a custom React Native template, like TypeScript, with —template argument:

Preparing the Android device

You will need an Android device to run your React Native Android app. This can be either a physical Android device, or more commonly, you can use an Android Virtual Device which allows you to emulate an Android device on your computer.

Either way, you will need to prepare the device to run Android apps for development.

Using a physical device

If you have a physical Android device, you can use it for development in place of an AVD by plugging it in to your computer using a USB cable and following the instructions here.

Using a virtual device

If you use Android Studio to open ./AwesomeProject/android , you can see the list of available Android Virtual Devices (AVDs) by opening the «AVD Manager» from within Android Studio. Look for an icon that looks like this:

If you have recently installed Android Studio, you will likely need to create a new AVD. Select «Create Virtual Device. «, then pick any Phone from the list and click «Next», then select the Q API Level 29 image.

We recommend configuring VM acceleration on your system to improve performance. Once you’ve followed those instructions, go back to the AVD Manager.

Click «Next» then «Finish» to create your AVD. At this point you should be able to click on the green triangle button next to your AVD to launch it, then proceed to the next step.

Running your React Native application

Step 1: Start Metro

First, you will need to start Metro, the JavaScript bundler that ships with React Native. Metro «takes in an entry file and various options, and returns a single JavaScript file that includes all your code and its dependencies.»—Metro Docs

To start Metro, run npx react-native start inside your React Native project folder:

react-native start starts Metro Bundler.

If you use the Yarn package manager, you can use yarn instead of npx when running React Native commands inside an existing project.

If you’re familiar with web development, Metro is a lot like webpack—for React Native apps. Unlike Kotlin or Java, JavaScript isn’t compiled—and neither is React Native. Bundling isn’t the same as compiling, but it can help improve startup performance and translate some platform-specific JavaScript into more widely supported JavaScript.

Step 2: Start your application

Let Metro Bundler run in its own terminal. Open a new terminal inside your React Native project folder. Run the following:

If everything is set up correctly, you should see your new app running in your Android emulator shortly.

npx react-native run-android is one way to run your app — you can also run it directly from within Android Studio.

If you can’t get this to work, see the Troubleshooting page.

Modifying your app

Now that you have successfully run the app, let’s modify it.

  • Open App.js in your text editor of choice and edit some lines.
  • Press the R key twice or select Reload from the Developer Menu ( Ctrl + M ) to see your changes!

That’s it!

Congratulations! You’ve successfully run and modified your first React Native app.

Now what?

  • If you want to add this new React Native code to an existing application, check out the Integration guide.

If you’re curious to learn more about React Native, check out the Introduction to React Native.

Unsupported​

A Mac is required to build projects with native code for iOS. You can follow the Expo CLI Quickstart to learn how to build your app using Expo instead.

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