Question: how to make dll file?
Answer: Click the File. ... 
Click New and Project. ... 
Set the options for Language, Platform, and Project Type. ... 
Click Platform to get a drop-down menu and click Windows.
Click Project Type to get a drop-down menu and click Library.
Click Dynamic-link Library (DLL). ... 
Type a name in the Name Box for the project. ... 
Click Create.