我开始学习如何在 android 环境中使用 ReactNative 进行移动编程。我正在使用 MacOS Catalina，并且已经安装了 android studio 和 react-native-cli。我跑react-native init ShoppingList过去了
Downloading template,
Copying template,
Processing template
但失败了，Installing CocoaPods dependencies因为我还没有使用最新的操作系统（我希望这不是问题的一部分，因为我没有足够的内存来升级操作系统）
我在这个问题中提到了一个建议，它要求我运行
npm uninstall -g react-native react-native-cli
npm install -g react-native react-native-cli
react-native start --reset-cache
我还删除了 node_modules 和npm install项目的根目录。然后在我运行的项目的根目录下react-native run-android。
这给了我以下错误
info Running jetifier to migrate libraries to AndroidX. You can disable it using "--no-jetifier" flag.
Jetifier found 967 file(s) to forward-jetify. Using 8 workers...
info Starting JS server...
/bin/sh: adb: command not found
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...
Deprecated Gradle features were used in this build, making it incompatible with Gradle 7.0.
Use '--warning-mode all' to show the individual deprecation warnings.
See https://docs.gradle.org/6.2/userguide/command_line_interface.html#sec:command_line_warnings
FAILURE: Build failed with an exception.
* What went wrong:
Could not determine the dependencies of task ':app:installDebug'.
> 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 '/Users/prashin/Test/ShoppingList/android/local.properties'.
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.
* Get more help at https://help.gradle.org
BUILD FAILED in 2s
error Failed to install the app. Make sure you have the Android development environment set up: https://reactnative.dev/docs/environment-setup. Run CLI with --verbose flag for more details.
Error: Command failed: ./gradlew app:installDebug -PreactNativeDevServerPort=8081
在 Android Studio 内部，安装了以下内容
Android 11.0(R),
Android SDK Build-Tools,
Android Emulator 30.2.6,
Android SDK-Platform-Tools 30.0.5,
Intel x86 Emulator Accelerator (HAXM installer) 7.5.1
Pixel 2 Device我用)创建了一个Release name R(API Level 30，并无数次按下播放按钮，它给了我的错误AVD Manager: Unable to locate ADB。
这是我的.bash_profile文件。
source ~/.profile
# Setting PATH for Python 3.7
# The original version is saved in .bash_profile.pysave
PATH="/Library/Frameworks/Python.framework/Versions/3.7/bin:${PATH}"
export PATH
export NVM_DIR="$HOME/.nvm"
[ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh" # This loads nvm
[ -s "$NVM_DIR/bash_completion" ] && \. "$NVM_DIR/bash_completion" # This loads nvm bash_completion
##
# Your previous /Users/prashin/.bash_profile file was backed up as /Users/prashin/.bash_profile.macports-saved_2019-10-23_at_18:32:04
##
# MacPorts Installer addition on 2019-10-23_at_18:32:04: adding an appropriate PATH variable for use with MacPorts.
export PATH="/opt/local/bin:/opt/local/sbin:$PATH"
export ANDROID_HOME=/Users/prashin/Library/Android/sdk
export ANDROID_SDK_ROOT=$ANDROID_HOME
export PATH="$PATH:$ANDROID_HOME/emulator:$ANDROID_HOME/tools:$ANDROID_HOME/platform-tools"
# export PATH="$PATH:/Users/$USER/Library/Android/sdk/platform-tools"
# export PATH=${PATH}:/usr/local/mysql-5.7.31-macos10.14-x86_64/bin
# Finished adapting your PATH environment variable for use with MacPorts.
根据这篇文章，我确实在平台工具中看到了一个 adb 可执行文件。
我可能会在这里遗漏什么阻止我在模拟器上运行我的基本应用程序？如果需要更多信息，请通知我。
编辑
建议的切换解决方案.zprofile改为更改错误消息。info launching emulator在产生以下错误之前，它卡住了 30 秒。
error Failed to launch emulator. Reason: Could not start emulator within 30 seconds..
warn Please launch an emulator manually or connect a device. Otherwise app may fail to launch.
info Installing the app...
> Task :app:stripDebugDebugSymbols UP-TO-DATE
Compatible side by side NDK version was not found.
> Task :app:installDebug FAILED
Skipping device 'emulator-5554' (emulator-5554): Device is OFFLINE.
Deprecated Gradle features were used in this build, making it incompatible with Gradle 7.0.
Use '--warning-mode all' to show the individual deprecation warnings.
See https://docs.gradle.org/6.2/userguide/command_line_interface.html#sec:command_line_warnings
27 actionable tasks: 2 executed, 25 up-to-date
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':app:installDebug'.
> com.android.builder.testing.api.DeviceException: No online devices found.
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.
* Get more help at https://help.gradle.org
BUILD FAILED in 4s
error Failed to install the app. Make sure you have the Android development environment set up: https://reactnative.dev/docs/environment-setup. Run CLI with --verbose flag for more details.
Error: Command failed: ./gradlew app:installDebug -PreactNativeDevServerPort=8081