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I have had 2 projects Dynamic Library C and Application C. I took a copy of header file from Dynamic Library into Application in Files Window. The problem is that I can't see that copied header file in section header files in Application Project Window. If I create header file from scratch I will have see icon file in the project tree.
This is actually not a bug. Managed projects (Applications, Dynamic Libraries, Static Libraries) are using so-called logical folders meaning the folder layout you see in the Projects view don't necessarily reflect the physical file structure. Projects view is the logical view. Files view is the physical file structure view. What you want to do is to copy the file in the Projects view. If you do, you will see the file correctly shows up in the the logical folder you copy it to. If you copy the file in the Files view, the file is copied to the other physical folder but not added to the project. You can however always add any file to one of the projects by using the action Add Existing File from the the project's context menu (in Project View).