I am porting some of the logic from old VB6 files to C#.
For easy reference, and to have the VB6 files available long-term for reference, I added them to my project and set the Build Action to None.
When I compile my project, I get over 100 errors in the Error List related to those files. If there are no other errors in the project, I get a Build Succeeded message and I can run or debug the project. If there are other errors, those errors are well-hidden among all of the VB6 related error messages.
I would prefer to keep the .bas file extension, because Visual Studio provides syntax highlighting that is mostly-useful, as VB6 and VB.Net share significant syntax.
How can I prevent Visual Studio from showing compile errors related to the VB6 file, and treat it simply as a reference document, without abandoning the .bas file extension?