React Native，为什么React Native运行的android不工作

Question

我试图运行命令react-native run-android，但它抛出了一个错误。我遵循了我遵循的每一步文档，但它不起作用，我认为它没有选择路径，但它设置如文档中所示。有人能告诉我怎么了吗？

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:UsersDanger' is not recognized as an internal or external command,
operable program or batch file.
info Launching emulator...
'C:UsersDanger' is not recognized as an internal or external command,
operable program or batch file.
'C:UsersDanger' is not recognized as an internal or external command,
operable program or batch file.
'C:UsersDanger' is not recognized as an internal or external command,
operable program or batch file.
'C:UsersDanger' is not recognized as an internal or external command,
operable program or batch file.
'C:UsersDanger' is not recognized as an internal or external command,
operable program or batch file.
'C:UsersDanger' is not recognized as an internal or external command,
operable program or batch file.
'C:UsersDanger' is not recognized as an internal or external command,
operable program or batch file.
'C:UsersDanger' is not recognized as an internal or external command,
operable program or batch file.
'C:UsersDanger' is not recognized as an internal or external command,
operable program or batch file.
'C:UsersDanger' is not recognized as an internal or external command,
operable program or batch file.
'C:UsersDanger' is not recognized as an internal or external command,
operable program or batch file.
'C:UsersDanger' is not recognized as an internal or external command,
operable program or batch file.
'C:UsersDanger' is not recognized as an internal or external command,
operable program or batch file.
'C:UsersDanger' is not recognized as an internal or external command,
operable program or batch file.
'C:UsersDanger' is not recognized as an internal or external command,
operable program or batch file.
'C:UsersDanger' is not recognized as an internal or external command,
operable program or batch file.
'C:UsersDanger' 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

这是我在安卓中运行react native后得到的错误

Answer 1

执行这些操作。

1. 请确保JDK版本为8或更新版本
2. 确保android路径设置正确
3. 删除android/build和android/app/build文件夹

编辑：如果JDK版本是14并且gradle版本<6.3>

Answer 2

似乎您的问题与：如何解决react native 中的(无法初始化类org.codehaus.groovy.reflection.ReflectionCache(问题有关

它还说，你有注册护士有麻烦启动一个模拟器。所以你可能需要自己启动它，或者连接真实的设备