修复 React-Native run-android 上的构建失败

Question

我是一个反应原生的新手。 我开始了一个新项目并遵循了所有步骤。 我之前有 Android Studio，我用它启动了模拟器。 运行 npx react-native run-android 命令后，我收到此错误。 这是

info Running jetifier to migrate libraries to AndroidX. You can disable it using "--no-jetifier" flag.
Jetifier found 870 file(s) to forward-jetify. Using 4 workers...
info JS server already running.
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...

> Task :app:compileDebugJavaWithJavac

> Task :app:stripDebugDebugSymbols
Unable to strip the following libraries, packaging them as they are: libbetter.so, libc++_shared.so, libevent-2.1.so, libevent_core-2.1.so, libevent_extra-2.1.so, libfabricjni.so, libfb.so, libfbjni.so, libflipper.so, libfolly_futures.so, libfolly_json.so, libglog.so, libglog_init.so, libhermes-executor-common-debug.so, libhermes-executor-common-release.so, libhermes-executor-debug.so, libhermes-executor-release.so, libhermes-inspector.so, libimagepipeline.so, libjsc.so, libjscexecutor.so, libjsi.so, libjsijniprofiler.so, libjsinspector.so, liblogger.so, libmapbufferjni.so, libnative-filters.so, libnative-imagetranscoder.so, libreact_codegen_rncore.so, libreact_debug.so, libreact_nativemodule_core.so, libreact_render_animations.so, libreact_render_attributedstring.so, libreact_render_componentregistry.so, libreact_render_core.so, libreact_render_debug.so, libreact_render_graphics.so, libreact_render_imagemanager.so, libreact_render_leakchecker.so, libreact_render_mapbuffer.so, libreact_render_mounting.so, libreact_render_runtimescheduler.so, libreact_render_scheduler.so, libreact_render_telemetry.so, libreact_render_templateprocessor.so, libreact_render_textlayoutmanager.so, libreact_render_uimanager.so, libreact_utils.so, libreactconfig.so, libreactnativeblob.so, libreactnativejni.so, libreactnativeutilsjni.so, libreactperfloggerjni.so, librrc_image.so, librrc_modal.so, librrc_progressbar.so, librrc_root.so, librrc_scrollview.so, librrc_slider.so, librrc_switch.so, librrc_text.so, librrc_textin
> Task :app:installDebug FAILED
31 actionable tasks: 31 executed
Note: E:\Coding\React Native\RNdasar\android\app\src\debug\java\com\rndasar\ReactNativeFlipper.java uses or overrides a deprecated API.
Note: Recompile with -Xlint:deprecation for details.

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':app:installDebug'.
> com.android.builder.testing.api.DeviceException: No connected devices!

* 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 1m 47s

error Failed to install the app. Make sure you have an Android emulator running or a device connected.
Error: Command failed: gradlew.bat app:installDebug -PreactNativeDevServerPort=8081
Note: E:\Coding\React Native\RNdasar\android\app\src\debug\java\com\rndasar\ReactNativeFlipper.java uses or overrides a deprecated API.
Note: Recompile with -Xlint:deprecation for details.

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':app:installDebug'.
> com.android.builder.testing.api.DeviceException: No connected devices!

* 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 1m 47s

    at makeError (E:\Coding\React Native\RNdasar\node_modules\execa\index.js:174:9)
    at E:\Coding\React Native\RNdasar\node_modules\execa\index.js:278:16
    at processTicksAndRejections (internal/process/task_queues.js:95:5)
    at async runOnAllDevices (E:\Coding\React Native\RNdasar\node_modules\@react-native-community\cli-platform-android\build\commands\runAndroid\runOnAllDevices.js:109:5)
    at async Command.handleAction (E:\Coding\React Native\RNdasar\node_modules\react-native\node_modules\@react-native-community\cli\build\index.js:192:9)
info Run CLI with --verbose flag for more details.

如何解决这个问题？

Answer 1

错误说没有连接设备。

意味着没有模拟器或设备连接到您的系统。

1. 如果您有模拟器，请在运行本机应用程序之前运行它。 如果没有，请先创建一个模拟器。

按照此链接创建一个：创建模拟器

2. 如果你想在手机上运行它。 用电缆连接它，然后在手机上打开 usb 调试。

希望这能解决你的问题