React Native，为什么 react-native run-android 不起作用？

Question

我正在尝试运行命令react-native run-android，但它抛出了一个错误。我正在关注我遵循每一步的文档，但它不起作用，我认为它没有选择路径，而是按照文档中所示设置。谁能告诉我怎么了？

info Running jetifier to migrate libraries to AndroidX. You can disable it using "--no-jetifier" flag.
(node:12536) Warning: Accessing non-existent property 'padLevels' of module exports inside circular dependency
(Use `node --trace-warnings ...` to show where the warning was created)
Jetifier found 967 file(s) to forward-jetify. Using 4 workers...
info Starting JS server...
'C:\Users\Danger' is not recognized as an internal or external command,
operable program or batch file.
info Launching emulator...
'C:\Users\Danger' is not recognized as an internal or external command,
operable program or batch file.
'C:\Users\Danger' is not recognized as an internal or external command,
operable program or batch file.
'C:\Users\Danger' is not recognized as an internal or external command,
operable program or batch file.
'C:\Users\Danger' is not recognized as an internal or external command,
operable program or batch file.
'C:\Users\Danger' is not recognized as an internal or external command,
operable program or batch file.
'C:\Users\Danger' is not recognized as an internal or external command,
operable program or batch file.
'C:\Users\Danger' is not recognized as an internal or external command,
operable program or batch file.
'C:\Users\Danger' is not recognized as an internal or external command,
operable program or batch file.
'C:\Users\Danger' is not recognized as an internal or external command,
operable program or batch file.
'C:\Users\Danger' is not recognized as an internal or external command,
operable program or batch file.
'C:\Users\Danger' is not recognized as an internal or external command,
operable program or batch file.
'C:\Users\Danger' is not recognized as an internal or external command,
operable program or batch file.
'C:\Users\Danger' is not recognized as an internal or external command,
operable program or batch file.
'C:\Users\Danger' is not recognized as an internal or external command,
operable program or batch file.
'C:\Users\Danger' is not recognized as an internal or external command,
operable program or batch file.
'C:\Users\Danger' is not recognized as an internal or external command,
operable program or batch file.
'C:\Users\Danger' is not recognized as an internal or external command,
operable program or batch file.
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...

FAILURE: Build failed with an exception.

* What went wrong:
Could not initialize class org.codehaus.groovy.runtime.InvokerHelper

* 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 17s

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.bat app:installDebug -PreactNativeDevServerPort=8081

这是我在 android 中运行 react native 后遇到的错误

Answer 1

做这些。

1. 确保 JDK 版本为 8 或更高版本。
2. 确保正确设置了 android 路径。
3. 删除 android/build 和 android/app/build 文件夹。

编辑： 如果 JDK 版本 为 14 且 gradle 版本低于 6.3 您必须将 JDK 降级到 11 或将 gradle 升级到 6.3 以上

Answer 2

您的问题似乎与：How solve (Could not initialize class org.codehaus.groovy.reflection.ReflectionCache) issue in react native

它还说您有 RN 在启动模拟器时遇到问题。所以你可能需要自己启动它，或者连接真实设备