Firstly, use vc write dll file, and then call vb；it has been through debugged.

VB调用VC的DLL(成功)\SerialCommDll1\main.cpp
...................\..............\main.dsp
...................\..............\main.dsw
...................\..............\main.ncb
...................\..............\main.opt
...................\..............\main.plg
...................\..............\SerialCommDll1.cpp
...................\..............\SerialCommDll1.def
...................\..............\SerialCommDll1.dsp
...................\..............\SerialCommDll1.dsw
...................\..............\SerialCommDll1.ncb
...................\..............\SerialCommDll1.opt
...................\..............\SerialCommDll1.plg
...................\..............\Debug\main.obj
...................\..............\.....\main.sbr
...................\..............\.....\SerialCommDll1.bsc
...................\..............\.....\SerialCommDll1.dll
...................\..............\.....\SerialCommDll1.exp
...................\..............\.....\SerialCommDll1.ilk
...................\..............\.....\SerialCommDll1.lib
...................\..............\.....\SerialCommDll1.obj
...................\..............\.....\SerialCommDll1.pdb
...................\..............\.....\SerialCommDll1.sbr
...................\..............\.....\vc60.idb
...................\..............\.....\vc60.pdb
...................\..........\Form1.frm
...................\..........\Module1.bas
...................\..........\MSSCCPRJ.SCC
...................\..........\Project1.vbp
...................\..........\Project1.vbw
...................\..........\SerialComm.exe
...................\..........\SerialCommDll1.dll
...................\..........Dll1\Debug
...................\..........\Debug
...................\SerialCommDll1
...................\SerialComm
VB调用VC的DLL(成功)

• We are an exchange download platform that only provides communication channels. The downloaded content comes from the internet. Except for download issues, please Google on your own.
• The downloaded content is provided for members to upload. If it unintentionally infringes on your copyright, please contact us.
• Please use Winrar for decompression tools
• If download fail, Try it againg or Feedback to us.
• If downloaded content did not match the introduction, Feedback to us，Confirm and will be refund.
• Before downloading, you can inquire through the uploaded person information

Nothing．