Windows操作系统:

我认为它与一个锁文件有关，所以我只是去了项目文件夹中的.gradle\buildOutputCleanup，删除了cache.properties.lock文件并重新构建了项目。它工作得很完美。

Mac用户:

你需要给gradle许可:

sudo gradle

在@Sean Stayns的回答中引用了一个场景，以防它能帮助到任何人:如果你把你的项目保存在谷歌Drive文件夹中——不要这样做。只需将项目移动到本地驱动器即可解决此问题。

In the case we were trying to solve, were were also getting the "It is currently in use by another Gradle instance" error and nothing we tried here worked. The process ID was unknown as well. It didn't immediately occur to me to ask where the project was being saved, so in case anyone new to Android Dev is saving their projects to a Google Drive folder, just move over to your local drive. I would have just left this as a comment in @Sean Stayns's answer, but I can't comment. Hopefully it benefits someone.

我在我的项目中也面临着同样的问题，但我通过使项目无效来解决这个问题，所以在android studio中遵循以下步骤

File -> Invalidate cache / Restart…

Android工作室将重新启动，您的问题应该得到解决。

这些答案我都试过了，包括杀死java进程，在HOME_DIR和project dir中删除.gradle，重启Android Studio，甚至重启OS。

它开始正常工作后，我启动gradle同步。

在Mac上遇到同样的问题时，以上这些方法对我都不起作用。但是，有效的方法是打开活动监视器并关闭正在运行的java进程。我还注意到生成了一个.hprof文件，我删除了它。在那之后，我运行了我的项目，它成功了。