What is the meaning of the dotted file icon in Visual Studio 2015 Solution Explorer for a .cs File?

Question

What does this dotted file icon mean? It's a .cs file but it is not behaving right in my project and I've noticed this separate icon in Solution Explorer:

I've checked the MSDN Documentation in three places

Another page at MSDN

Yet another page at MSDN

I've also checked the Visual Studio Documentation itself, which is rather obscurely organized.

I've even checked this website:

Lastly, I found this topic with a similar question but both the question page and the references inside do not have this icon. Thanks for your help.

Answer 1

This means that the file isn't included in the project. You're only seeing it because you turned on Show All Files.

You should right-click the file and click Include in Project.

Answer 2

That "dotted" icon mean that that file is not a part of your project or it is hidden and it is not included in your project.

That "dotted" icon is pretty similar to the icon in Solution Explorer called "Show all files". When you click on it you can see all the files and maybe you click on it or you have some issue and your file is not included in the project.

To include it you can right click one of those files go to Include In Project and that will add it to the project, which declares it in the manifest of your project. You can do it like this: