XCode can not show the project's code files

Today I open my project, and find all the projects code files can not show up. At first I think that's the issue of git. So i do many operations about git,but it is still. So I think that's the xcode's setting issue.

Just google it,I got the result. Only need to do like this:

XCode menu -> Navigate -> Reveal in Project Navigator

Then all the files will show normally.

That's it.

Thanks,

Blues