我正在尝试使用android构建Unity 3D项目，但出现以下错误：
如果有人可以帮助我。在我的插件中，我有一个AdMob文件夹，但它可以正常工作，因为它适用于过去的项目。
UnityEditor.BuildPlayerWindow+BuildMethodException: 2 errors
at UnityEditor.BuildPlayerWindow+DefaultBuildMethods.BuildPlayer (BuildPlayerOptions options) [0x0021f] in C:\buildslave\unity\build\Editor\Mono\BuildPlayerWindowBuildMethods.cs:182
at UnityEditor.BuildPlayerWindow.CallBuildMethods (Boolean askForBuildLocation, BuildOptions defaultBuildOptions) [0x00065] in C:\buildslave\unity\build\Editor\Mono\BuildPlayerWindowBuildMethods.cs:89
UnityEditor.BuildPlayerWindow:BuildPlayerAndRun()
Build completed with a result of 'Failed'
UnityEditor.BuildPlayerWindow:BuildPlayerAndRun()
CommandInvokationFailure: Gradle build failed.
C:/Program Files/Java/jdk1.8.0_171\bin\java.exe -classpath "C:\Program Files\Unity\Editor\Data\PlaybackEngines\AndroidPlayer\Tools\gradle\lib\gradle-launcher-4.0.1.jar" org.gradle.launcher.GradleMain "-Dorg.gradle.jvmargs=-Xmx2048m" "assembleRelease"
stderr[
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':transformClassesWithDexForRelease'.
> com.android.build.api.transform.TransformException: com.android.ide.common.process.ProcessException: java.util.concurrent.ExecutionException: com.android.dex.DexException: Multiple dex files define Lcom/unity3d/ads/BuildConfig;
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.
BUILD FAILED in 5s
]
stdout[
NDK is missing a "platforms" directory.
If you are using NDK, verify the ndk.dir is set to a valid NDK directory. It is currently set to C:\Users\Drive Along\AppData\Local\Android\Sdk\ndk-bundle.
If you are not using NDK, unset the NDK variable from ANDROID_NDK_HOME or local.properties to remove this warning.
The setTestClassesDir(File) method has been deprecated and is scheduled to be removed in Gradle 5.0. Please use the setTestClassesDirs(FileCollection) method instead.
The getTestClassesDir() method has been deprecated and is scheduled to be removed in Gradle 5.0. Please use the getTestClassesDirs() method instead.
The ConfigurableReport.setDestination(Object) method has been deprecated and is scheduled to be removed in Gradle 5.0. Please use the method ConfigurableReport.setDestination(File) instead.
:preBuild UP-TO-DATE
:preReleaseBuild UP-TO-DATE
:checkReleaseManifest
:preDebugBuild UP-TO-DATE
:prepareAdmoblibReleaseLibrary
:preparePlayServicesAds1500Library
:preparePlayServicesAdsBase1500Library
:preparePlayServicesAdsIdentifier1501Library
:preparePlayServicesAdsLite1500Library
:preparePlayServicesBasement1501Library
:preparePlayServicesGass1500Library
:prepareSupportCompat2531Library
:prepareSupportV42531Library
:prepareUnityAdapter2100Library
:prepareUnityAdsLibrary
:prepareUnityAdsSdk21Library
:prepareReleaseDependencies
:compileReleaseAidl UP-TO-DATE
:compileReleaseRenderscript UP-TO-DATE
:generateReleaseBuildConfig UP-TO-DATE
:generateReleaseResValues UP-TO-DATE
:generateReleaseResources UP-TO-DATE
:mergeReleaseResources UP-TO-DATE
:processReleaseManifest
:processReleaseResources
:generateReleaseSources
:incrementalReleaseJavaCompilationSafeguard UP-TO-DATE
:javaPreCompileRelease
:compileReleaseJavaWithJavac UP-TO-DATE
:compileReleaseNdk NO-SOURCE
:compileReleaseSources UP-TO-DATE
:lintVitalRelease
:mergeReleaseShaders UP-TO-DATE
:compileReleaseShaders UP-TO-DATE
:generateReleaseAssets UP-TO-DATE
:mergeReleaseAssets
:transformClassesWithDexForRelease FAILED
29 actionable tasks: 20 executed, 9 up-to-date
]
exit code: 1
UnityEditor.Android.Command.WaitForProgramToRun (UnityEditor.Utils.Program p, UnityEditor.Android.WaitingForProcessToExit waitingForProcessToExit, System.String errorMsg)
UnityEditor.Android.Command.Run (System.Diagnostics.ProcessStartInfo psi, UnityEditor.Android.WaitingForProcessToExit waitingForProcessToExit, System.String errorMsg)
UnityEditor.Android.AndroidJavaTools.RunJava (System.String args, System.String workingdir, System.Action`1 progress, System.String error)
UnityEditor.Android.GradleWrapper.Run (System.String workingdir, System.String task, System.Action`1 progress)
Rethrow as GradleInvokationException: Gradle build failed
UnityEditor.Android.GradleWrapper.Run (System.String workingdir, System.String task, System.Action`1 progress)
UnityEditor.Android.PostProcessor.Tasks.BuildGradleProject.Execute (UnityEditor.Android.PostProcessor.PostProcessorContext context)
UnityEditor.Android.PostProcessor.PostProcessRunner.RunAllTasks (UnityEditor.Android.PostProcessor.PostProcessorContext context)
UnityEditor.BuildPlayerWindow:BuildPlayerAndRun()