这意味着该项目文件夹仍然在你的项目工作区文件夹存在。你可以把它并将它粘贴在其他地方，然后将其导入。或者你可能是幸运的，在eclipse刷新该文件夹就足够了。

That means that the project folder is still existing in your project workspace folder. You could cut it and paste it somewhere else, then import it. Or you might be lucky and refreshing the folder in eclipse is enough.