My preference is: If it's modified by the build system, ensure the build process will create it and don't check it in.
For autogenerated files like 'designer', I check them in. They only get modified when other components get changed (by me). It's generated by VS and not modified by the build system.
与恶龙缠斗过久,自身亦成为恶龙；凝视深渊过久,深渊将回以凝视…
