使用 Java 常量时未解决的引用

Question

当我尝试构建时，ide 抛出错误：“未解析的引用：X”

X 是（公共）类 Java 上的任何 Java 常量（public static final）

不能使用：

android.os.Environment.DIRECTORY_DOCUMENTS
Build.VERSION_CODES.M
Etc

我试过了：

Invalidate Cache in Android Studio
gradlew cleanBuildCache
Clean / Rebuild
Clone project on other folder,
Etc

这是一个混合项目，Java 和 Kotlin

我可以使用静态方法，例如：

public static Uri getUriForFile from public class FileProvider
Etc

错误行：

10:38:23.053 [ERROR] [org.gradle.api.Task] e: C:\Users\User\AndroidStudioProjects\MyAndroidProject\app\src\main\kotlin\com\myapp\mypackage\android\PermissionsHelper.kt: (67, 66): Unresolved reference: M

我正在使用：

Gradle 配置

ext.kotlin_version = ‘1.3.10’
classpath ‘com.android.tools.build:gradle:3.2.1’
androidExtensions { experimental = true }

软件

Windows 10 Pro 10.0.17134 N/D Compilation 17134 x64

Android Studio 3.2.1 Build #Al-181-5540.7.32.5056338,build on Octubre 8, 2018

java version “1.8.0_162”
Java™ SE Runtime Environment (build 1.8.0_162-b12)
Java HotSpot™ 64-Bit Server VM (build 25.162-b12, mixed mode)

堆栈跟踪：

10:38:23.076 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter] FAILURE: Build failed with an exception.
10:38:23.076 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter] 
10:38:23.076 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter] * What went wrong:
10:38:23.076 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter] Execution failed for task ':app:compileDebugKotlin'.
10:38:23.076 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter] > Compilation error. See log for more details
10:38:23.076 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter] 
10:38:23.076 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter] * Try:
10:38:23.076 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter]  Run with --scan to get full insights.
10:38:23.076 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter] 
10:38:23.076 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter] * Exception is:
10:38:23.077 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter] org.gradle.api.tasks.TaskExecutionException: Execution failed for task ':app:compileDebugKotlin'.
10:38:23.077 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter]   at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:103)
10:38:23.077 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter]   at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.execute(ExecuteActionsTaskExecuter.java:73)
10:38:23.077 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter]   at org.gradle.api.internal.tasks.execution.OutputDirectoryCreatingTaskExecuter.execute(OutputDirectoryCreatingTaskExecuter.java:51)
10:38:23.077 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter]   at org.gradle.api.internal.tasks.execution.SkipCachedTaskExecuter.execute(SkipCachedTaskExecuter.java:103)
10:38:23.077 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter]   at org.gradle.api.internal.tasks.execution.SkipUpToDateTaskExecuter.execute(SkipUpToDateTaskExecuter.java:59)
10:38:23.077 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter]   at org.gradle.api.internal.tasks.execution.ResolveTaskOutputCachingStateExecuter.execute(ResolveTaskOutputCachingStateExecuter.java:54)
10:38:23.077 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter]   at org.gradle.api.internal.tasks.execution.ResolveBuildCacheKeyExecuter.execute(ResolveBuildCacheKeyExecuter.java:66)
10:38:23.077 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter]   at org.gradle.api.internal.tasks.execution.ValidatingTaskExecuter.execute(ValidatingTaskExecuter.java:59)
10:38:23.077 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter]   at org.gradle.api.internal.tasks.execution.SkipEmptySourceFilesTaskExecuter.execute(SkipEmptySourceFilesTaskExecuter.java:101)
10:38:23.077 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter]   at org.gradle.api.internal.tasks.execution.FinalizeInputFilePropertiesTaskExecuter.execute(FinalizeInputFilePropertiesTaskExecuter

Answer 1

感谢 @yole 和 @Rod_Algonquin 的帮助，同时我正在写问题并回答问题，Rubber duck method 帮助我，IDE 是给我一个错误“未解决的参考”，但问题是注释：

@RequiresApi(Build.VERSION_CODES.M)

因为：minSdkVersion 16

我正在处理 PermissionsHelper.kt，我使用的是 Activity 而不是 android.support.v4.app.Fragment 或 ContextCompat 用于旧版本。

对不起，没有发布代码，完整的 gradle，我想做一个简短的帖子，这是我的第一个帖子。

感谢大家的帮助。