参考引用：https://stackoverflow.com/questions/33751509/external-assembly-file-in-visual-studio
the project is highlighted in the Solution Explorer and and choose PROJECT - Build Customizations… from the menu.
In the next window tick masm(.targets,.props) and click on OK.
In the Property Page you should see at least:
Excluded From Build (empty) or No
Item Type Microsoft Macro Assembler