使用 "expo start" 启动应用程序时没有问题，但打开 "yarn react-native run-android" 时出现问题

No problem when starting app with "expo start" but problem when opening "yarn react-native run-android"

如 header 中所写，应用程序在我从 expo 开始时执行，但是当我尝试 运行 和 Vscode 中的 yarn react-native run-android 时出现许多问题行。

warning ..\package.json: No license field
$ "C:\Users\SAMSUNG\Desktop\React Native Projects\Uber\node_modules\.bin\react-native" run-android
info Running jetifier to migrate libraries to AndroidX. You can disable it using "--no-jetifier" flag.
Jetifier found 1075 file(s) to forward-jetify. Using 4 workers...
info JS server already running.
'adb' is not recognized as an internal or external command,
operable program or batch file.
info Launching emulator...
error Failed to launch emulator. Reason: No emulators found as an output of `emulator -list-avds`.
warn Please launch an emulator manually or connect a device. Otherwise app may fail to launch.
info Installing the app...

> Configure project :expo

BUILD FAILED in 19s

error Failed to install the app. Make sure you have the Android development environment set up: https://reactnative.dev/docs/environment-setup.
Error: Command failed: gradlew.bat app:installDebug -PreactNativeDevServerPort=8081
Error: Autolinking is not set up in `settings.gradle`: expo modules won't be autolinked.

FAILURE: Build failed with an exception.

* What went wrong:
Could not determine the dependencies of task ':app:compileDebugJavaWithJavac'.
> SDK location not found. Define location with an ANDROID_SDK_ROOT environment variable or by setting the sdk.dir path in your project's local
properties file at 'C:\Users\SAMSUNG\Desktop\React Native Projects\Uber\android\local.properties'.

即使我在 android 中创建了一个名为 local.properties 的文件并写入 

sdk.dir=D\:\AndroidSDK

这两个代码在做不同的工作吗？如果编码部分有问题，为什么其中一个执行没有问题？

React Native 有 2 种解决方法：

  1. React Native CLI - 对于需要本机模块和手动配置 Android Studio 和 Xcode.

    的应用程序

  2. Expo CLI - SDK 建立在 React Native 之上。 Expo 提供易于使用的工具和 API 以及由云 Expo Server 基础架构完成的本机模块编译。

通过 运行ning expo start，Expo CLI 启动一个服务器，将您的应用程序代码提供给您设备或模拟器上的 Expo Go 应用程序。您的本地设备上没有本地模块编译，也不需要 Android SDK。

另一方面，当您运行 yarn react-native run android 时，必须安装和配置Java JDK 和Android SDK 才能编译本机模块。

在 https://reactnative.dev/docs/environment-setup

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