对我来说，从项目目录中删除。idea文件夹是可行的。

我已经删除了。idea文件夹。关闭ItelliJ并重新启动以打开相同的项目。

它要求添加内容根。这对我很管用。

我有一个nodeJs项目，删除/[project_name]后丢失了我的文件夹。安恩科技文件。

这恢复文件夹，同时保留我的其他项目设置:

项目设置>模块 +添加内容根目录

因为我有同样的问题，上面没有一个对我有效，这就是我所做的!我知道这是一个暴躁的解决方案，但至少它最终起作用了!我不知道为什么只有这种方法有效。应该是我电脑里的某个奇怪缓存吧?

I did close IntelliJ I did completely remove the .idea folder from my project I did move the folder demo-project to demo-project-temp I did create a new empty folder demo-project I did open this empty folder with intelliJ I did move all the content demo-project-temp. Don't forget to also move the hidden files Press right click "Synchronize" to your project You should see all the files and folders now! Now you can also safely remove the folder demo-project-temp. If you are on linux or MAC do it with rmdir demo-project-temp just to make sure that your folder is empty

I have a better solution that worked for me and it might work for you. No need to delete the whole .idea folder as this way you lose the whole project. It is possible that you just accidentally excluded all folders in project settings. I also found that project folders disappeared. I was trying to find out how to disable indexing, so I was looking at Project Settings -> Modules and I clicked on Excluded to see if I could add the whole project there to ignore it for indexing. It didn't do anything and I couldn't drag and drop the folder under Excluded. What I didn't realize is that simply clicking "Excluded", IntelliJ automatically moves the folder to Excluded and all folders disappeared in Project Explorer. "Excluded" button changes background to gray, which means exclusion is active. This is a very poor user interface because it is hardly noticeable and clicking this button has a far-reaching impact on your project.

Fix:

打开项目设置->模块 如果“排除”突出显示，单击它 单击应用或关闭

结果: 项目中的文件夹再次显示出来

非常糟糕的UI设计!源和排除按钮看起来像标签时，他们的工作实际上是“复选框”!

注意，仅仅单击Sources或Excluded似乎是一个没有任何可见效果的选项卡选择，但它具有深远的影响，基本上是从构建过程中添加或删除文件。

删除.idea/workspace.xml对我有用。关闭项目，删除.idea/workspace.xml，然后重新打开项目。我使用的是2019.1版本。